Character mistake: While looking at a doctored photo of Lincoln and his mother, Lincoln mentions that Michael was born in 1976, but at the end of "Killing Your Number", it reads on Michael's grave stone that he was born in 1974.
Factual error: The Indian Embassy guard is wearing a Canadian Forces military hat when in fact he is suppose to wear the Indian Army hat. (00:16:00 - 00:20:00)
Continuity mistake: Sucre and C-Note came to Michael's help with dealing with the general. Sucre has noticeably longer hair than normal. In the next clip his hair is gone. (00:20:00 - 00:21:00)
Other mistake: While Paul Kellerman talks to Lincoln about Sofia and LJ, Dominic Purcell has a tattoo on his left forearm saying "j.c. 1950-2008", which should have been hidden as season 4 is set in 2005. (00:40:57)
Other mistake: Sarah and Michael are walking along the beach at the end. There is quite a clear path disturbed in front of them from where they practiced the shot before.
Answer: Because of coincidence.