Continuity mistake: After the gun goes off during his fight with Yankovski, blood appears on the right side of Rollin's mouth: it wasn't there a moment before. And a few shots later, the blood is on the left, then changes back to the right. (One shot in the sequence was, for some reason, flipped.)
Continuity mistake: After Rollin is in a fist fight he has blood on the left side of his mouth. After a quick scene switch to another person when it goes back to him the blood is on the right side. Another quick switch and back to him, the blood is back to his left side.