When Sandy and Kirsten is at swingers party and Sandy s about to put his watch in the bowl, one shot his hand is near the bowl, but seconds later the hand with the watch is near his ear.
At the swingers party, it is Taryn's turn to pull a watch. In the shot where she sticks her hand in the bowl, you can clearly see that she pulls a gold watch. The next shot she's seen pulling a totally different watch.
GPS says to turn left and Sandy says he's going to defy the GPS and go right instead. An establishing shot shows Sandy turns on his right signal, but still turns left following the GPS instructions. However, back inside the car, the GPS instructs Sandy to "make a U-turn".
Hailey locks Seth and Ryan in the pool house from the outside. Even if the knobs and deadbolts only used keys on both sides, Ryan should have a key since he sleeps in the pool house. Only having locks on the outside doesn't make sense for this reason either. Ryan wouldn't have a way to lock up when he goes to bed. Hailey also only locks one set of doors, and there are at least 2 sets of doors to get into the pool house.