Corrected entry: In the Mariachi's flashback, where he gets shot in the hand, if it's seen in slow-mo, the "blood" is being shot onto his hand from off the right side of the screen. (As per the rules on the contribution page, there are exceptions to using slow-mo: "...something else fairly major is worth listing" and this falls under that rule.)
Corrected entry: The gun that the bookie fires at Banderas in the bar has a silencer on it, but when he fires the gun at him, it sounds like normal gunfire.
Corrected entry: In the very last scene when Antonio Banderas is throwing away his guitar case, you can see that the car Salma Hayek is driving is rather high. Anyway, when they go back to pick the case up again, Antonio Banderas opens the door and reaches out a bit to get it. Considering the height of the car, it's impossible for him to get it from that angle. (01:35:20)
Corrected entry: El Mariachi is crouching with Carolina in his arms during the scene on the rooftop, watching Bucho and his men arrive at the burning bookstore across the street. They were in open view, near the roof's edge, yet none of Bucho's men saw them even when facing that direction. Are the thugs all blind?
Corrected entry: When El Mariachi walks into the Tarassco bar before the gunfight, the bartender tells him about a guy with a "Guitar case full of guns". In the opening scene of the movie Steve Buscemi never tells the same bartender or the thugs in the Tarassco bar what kind of case El Mariachi is carrying.
Corrected entry: Right after Antonio pulls the 3 knives out of his body, he is seen walking and leaning on a wall and leaving a trail of blood behind him as he walks. The next shot shows him leaned up against the wall not moving and the trail of blood is no longer on the wall.
Corrected entry: When the bar villains jump over the bar to get the Mariachi, one of them yells, "Come, mes amis!" which is French. They're all supposed to be Mexican.