Despite being beaten to a pulp and having numerous visual cuts and bruises on her face and neck among other places, there are absolutely no marks on her as she and her little sister are waiting in at the airport just a day or so later. It's evident that not more than a day or two had passed since the encounter, as the story was just being aired on the news.
When The Blind Man fires the Beretta point blank at Alex's head towards the end of the movie, it clicks because he's out of ammo; but when a semiautomatic pistol fires its last round, the slide does not go forward but locks back, so the empty magazine can be released and a full magazine can be placed in the magazine well. After that is done, the slide is pulled back a bit and then let go; this action chambers a new round.
When Rocky is removing the cash from the safe, the cash straps are blue. American Bankers Association blue straps are for $1 bills in increments of 100 ($100). She is shown removing 8 stacks, the only clearly visible stack contains 7 straps. That's $5,600.
After discovering intruders the blind man decides to board up his house from the inside. He is shown putting a perfectly fitted/cut piece of plywood over a window. The odds of him having plywood already cut to board up his house from the inside seem ridiculously low.
Based on the trio's habit of leaving DNA traces all around the houses they break into, like Rocky leaving her hair behind in the beginning of the movie (lying on the bed, etc.), they should have been caught by the police by the time they break into the blind man's house.
Towards the end of the film, a character fires a shot which hits a framed photograph. The picture falls away, revealing no damage to the wall behind it. It's safe to assume that the bullet would not have lodged in the photograph.
Gunfire in an enclosed space is exceptionally loud. So loud that it can permanently damage hearing and will result in temporary hearing loss. Despite this, multiple rounds are fired and yet even a blind character who is shown to be dependent upon his hearing is unaffected by the sounds.
The goof items below may give away important plot points.
When Alex and Rocky shut themselves in Emma's bedroom, they realise they are trapped, because there are bars on all of the windows. But when the dog burst in, it charges at Alex and the next thing we see, he's flown out of the window.
The police units arriving at the antagonist's home can clearly see Rocky from the home's yard and across the street as they are driving up. Not only does no one follow her, but she somehow escapes despite being parked only a few yards away from the home.