Other mistake: Michael goes to Fox River in April. Maricruz gets pregnant in the same month. In mid-June, when Michael get arrested in Panama, she's still pregnant. That's 2 months. He was in there for about 2 weeks, due to his deal with the company. Therefore, he would have escaped Sona at the end of June or the start of July. The start of Season 4 is set 3 weeks after the escape from Sona, so Maricruz should be 3 months pregnant, but gives birth at the start of season 4, meaning that the baby is 6 months early but looks very healthy.
Prison Break (2005)
3 mistakes in Scylla
Starring: Dominic Purcell, Robert Knepper, Wentworth Miller, Amaury Nolasco
Riots, Drills and the Devil: Part 1 - S1-E6
T-Bag: Can't you transfer us some place cooler? Like Africa? (00:16:20)
Trivia: The show was filmed in an actual prison (now unused) in Joliet. The death row cell used for Lincoln Burrows is the actual death row cell that held serial killer John Wayne Gacy.
More questions & answers from Prison Break
Answer: Because of coincidence.