Deliberate mistake: Spoilers! When Black Manta is defeated, he is knocked unconscious and tumbles down a rock face after his helmet explodes on his face into the waters by the shores of Sicily. These currents and waves at best would have carried him to the rocks or the beach, leaving him on land or near it. However in the after credit scene he's somehow found out in the middle of the ocean on a broken drift wood. He would not have been carried back out to sea like that.
Suggested correction: The water is tidal. If the tide was going out, the current would take him out to sea.
There are hardly any tides in the Mediterranean Sea http://scienceline.ucsb.edu/getkey.php?key=995.
Deliberate mistake: An LAPD cop discharges his firearm a full size Glock which has a minimum magazine capacity of 13+1 for the Glock 21. The Glock 21 is approved LAPD issue along with other variants. He fires maybe three shots and the slide locks back signalling that it's dry. A second later the same cop is walking with the same empty Glock aimed towards the suspect which was shot at. It's visible that the slide is being held back by the slide stop since the magazine went dry. (01:29:58)
Deliberate mistake: After Venom eats the head of one of the Drake's henchmen there is no blood from the wound.
Deliberate mistake: When Michelle brings up the photo of "Fake Denzel" on her phone, she says she put it into a hidden folder. Problem? She only presses on her phone once (based on the sound you hear), and has the photo up and filling the screen within about one second. Totally preposterous. Obviously, it was done that way to keep the scene moving quickly... but there's no way a single button press and a timespan of about one second is going to bring up and maximize a photo from a hidden folder on her phone.
Suggested correction: The very faint click you hear could be her phone unlocking, so we don't know how often she taps the screen. That said, yes, it's unlikely she'd be able to access the photo that fast.
I don't understand this correction, because it literally just seems to reinforce the original mistake. Unlocking her phone wouldn't instantly bring up a photo in a hidden folder.
Deliberate mistake: When Walker leaves the tunnels in London and Hunt follows him, they both start their way to the Tate Modern Museum at Queens Head Passage / Paternoster Row. While Hunt is being chased and cannot choose his route, besides not knowing about Walker's destination, Walker deliberately takes a detour to Blackfriars Station and the bridge, even though he could just have walked a direct line from St. Paul's Cathedral towards Tate Modern using Millennium Bridge to directly cross to the museum and his getaway. The whole chase sequence would be obsolete. (01:31:58 - 01:36:56)
Deliberate mistake: For dramatic purposes, the crew is shown surviving for several days. The investigators found evidence that the fire in the compartment occurred around six hours after the Kursk sank, and that the survivors had died before the first rescue attempt took place. They wouldn't have been saved even if the multinational team had been called in sooner.