Continuity mistake: When Mando switches on the jetpack, the reaction shot on Cara Dune is flipped. In the same shot, Mando also has the jetpack mistakenly still in hand, but he already put it on his back. (00:38:15)
Continuity mistake: Somehow without being challenged, the imperials put explosive on the door of the cantina and blow it open, nearly flushing out Cara. More pew-pew action ensues, Mando is critically wounded, and his pals drag him back to the cantina and...close the door behind them. The building grew a door back? (00:17:05 - 00:18:30)
Plot hole: Mando thinks that the other Mandalorians are alive, that they will definitely help him (but then why didn't he contact them?), and even presumes that they are still hiding in the same sewers as before, when it was stated at the end of 1-3 that they'd have to relocate, and he knows now that the planet is under imperial control. Still, he is not wrong, and despite most of the Mandalorians having died, their precious armor lie there even days or weeks after.
Plot hole: Moff Gideon can count on a plethora of forces (as seen in Season 2) and as a calculating villain who does not value at all the lives of his men, he should go and regroup. Instead, he engages Mando and the others firing at their boat, which if successful, would atomize the Child, making his mission entirely for naught.
Plot hole: Weeks if not months have passed since Mando has been on Nevarro, with the power shift and the Empire taking control. The Mandalorian community was small, but he finds the Armorer in the old lair that says that she will leave only when she will have salvaged what remains. Since 'what remains' is a pile of armor pieces, and she is carrying already a cart full of those, it appears absurd that she'd still not finished with that task, especially considering that we see how the smelting process is pretty swift (she melts an armor piece and shapes it into the signet in the space of a brief conversation!) and even if every single one of the Mandalorians left their armor behind, it'd be just a couple of carts' worth of metal.
Suggested correction: This entry presumes that the armorer has done nothing but collect armor pieces, and plans to continue doing nothing but collect armor pieces until she is finished. She never says that. She merely says that she won't leave until she is done collecting everything. She could be doing any number of other tasks she never says anything about because it isn't important. It is also never said when she started collecting armor pieces, it could have been just before we see her.
We can make all sorts of assumptions; she was grieving for a time, she had to go into hiding, she had to collect the armor pieces from various places? Fascinating, but if we do not presume anything, what we get is the Armorer (known as and for just that) salvaging armor (saying "I will not abandon this place until I have salvaged what remains") at a place established as raided a long time ago. What she had to salvage was meager (just a handful of Mandos) and does it fast.
In order to be a plot hole it would have to be impossible for the armorer to take this long to collect armor pieces. Since we don't know everything she has been doing off-screen, this doesn't count as a plot hole. You have to ignore all logical and reasonable possibilities to get to the point where this is a plot hole, and you list more than one in your reply.
I listed them because they are the kind of things we can assume to justify "Events or character decisions which only exist to benefit the plot, rather than making sense.", definition of plot hole in the website. We can make up all sort of background story, but nothing changes the fact that a character is at a place raided weeks prior and in the middle of performing a task that the way shown here is not going to take more than a few hours.
It's the "rather than making sense" part that this entry lacks. There are several reasons that make sense why this could take long, chief among them the fact that we don't know how long she has actually been collecting armor pieces. If, for example she said "I've been doing this since the attack", that would be one thing. She doesn't say that. She just says she won't leave until this particular task is done, not that it was her only task. She could have just started.
Collecting armor as specific task is something I find as such for the first time in your first comment. The attack happened shortly after Mando left, and the planet has been under a tight Imperial control since. Nothing leads to believe that the pile of amor is not salvaged but was brought back through some quest that stretched out for weeks until she finally decided exactly that day to start carting them to the furnace, which is what she's in the middle of when they arrive.
Continuity mistake: The door of the bar Cara Dune is hiding in, is blown out of the doorframe by a trooper, but later it's back and fully repaired, and IG-11 closes it. (00:17:21 - 00:18:31)
Continuity mistake: When IG-11 is making its way through the city with a cartoonish trail of explosions, Greef Karga is having a drink. There's a sudden cut, and in the second shot the glowy liquid in the bottle is bouncing around very noticeably as if the bottle (or the whole counter) was just moved/knocked, which did not happen in the previous shot. (00:15:45)
Continuity mistake: When the nerdy Moff namedrops Mando and Greef's real identities, the shots from the waist up are mirrored; look at the position of the buttons on his Darth Vader-esque chestplate. (00:08:30)
Continuity mistake: After the comedy skit with the two scout troopers is over, the ground in front of Moff Gideon is in the shade or sunlit depending on the camera angle. (00:06:00)
Continuity mistake: The Scout Troopers have finished their shooting game. One of them gets up and the other looks bored (and annoyed because he does not get to see the 'package'). He is leaning against the bike's handle, or not, depending on the shot. (00:04:10)
Continuity mistake: Greef Karga moves his coat to access his holster, which is empty, until it isn't. (00:26:47)
Continuity mistake: After getting pulled and ragdolled around by it, Mando lands on the TIE fighter somehow with still both arms and decides to start shooting Moff Gideon. When he splats like a fly on the cockpit window he has nothing in hand, but at the cut he suddenly has his gun. (00:38:40)
Continuity mistake: When Greef Karga follows Mando outside the cantina to go support IG-11's sortie, he comes out of the door which has a large shadow area to the right of the frame, gone in the next camera angle. (00:16:25)
Character mistake: During the comedy moment with the scout troopers, the radio person tells them that Gideon just killed an officer for interrupting. Nothing of the sort happens during the sequence when Gideon is talking to the heroes.
Continuity mistake: Moff Gideon is able to best Mando also because he turns twice; he already has brought the heavy E-Web machine gun from shoulder level once, but Gideon notices the power unit and switches target when Mando is repeating the movement. (00:18:05)
Plot hole: The flamethrowing trooper enters, entirely on his own, walking slowly through the door, and neither Cara nor Greef, who are armed and not wounded, shoot at him, for no discernible reason other than giving the Child a little pyromancer moment. And of course, Gideon wants the baby ALIVE; burning the place to a crisp kinda goes against all of that, but he is the one who ordered that. (00:20:50)
