Other mistake: As Vera is trying to get into the room where Marv is, Kevin is playing insults with Marv's voice loud enough for Vera to hear through the door. She enters the room and Marv is oblivious to why she's angry at him as if he didn't hear the playback, despite being in the room as they were played in.
Other mistake: When Marv and Vera first break in the house, they enter the bathroom through Kevin's room, the door wide open. Kevin turns on the shower and floods the house. Kevin's room would've been flooded as the door was open.