Other mistake: When Cloud and Aerith visit the first 'Sephiroth clone', in Sector 5 in Midgar, she says to him "This guy are sick". That is a translation error and should say "This guy is sick".
Other mistake: After you defeat Jenova-Life, it says "Beacause you are a puppet." "Beacause" should be "Because".
Continuity mistake: In the FMV when Sephiroth kills Aerith, you can see her pink ribbon fall off. But after the FMV is over, it reappears.
Continuity mistake: When Sephiroth jumps down to kill Aerith, we see a close up of him not wearing any gloves. Then gloves suddenly appear on his hands as he kills her when the camera angle changes.