While rotten meat can certainly have maggots in it, the maggots would not still be alive after the meat has been cooked.
Madison Square Garden has a Mixed Martial Arts (MMA) Octagon in it. The zombie apocalypse occurred in 2010 and the State of New York did not allow MMA fights at the time, only doing so in 2016, 6 years after the end of civilization.
Correction: It would have been easy enough for the people living in the stadium to find an MMA ring somewhere else and set it up, or even build their own.
Correction: It would have been easy enough for the people living in the stadium to find an MMA ring somewhere else and set it up, or even build their own.
During the cage fight, a zombie has his head ripped off, causing blood to spurt out from the stump. Since zombies are dead, blood would not spurt out as the heart is no longer beating.
Every car on the streets of New York has the yellow "Empire Gold" license plate. That license plate was brand-new when the zombie apocalypse occurred (c. August 2010), so only a few cars would have had it then. Most cars would have still been using the blue-and-white Niagara Falls license plate design introduced in 2001.
Maggie is seen looking at pictures of her family. As in the original series she escaped the farm with the clothes on her back, there is no way that she would have pictures of her family all the years later.