Soooo...
...If you are able to get out of a bed were you are being restrained and fool the guy that is restraining you for some mad experience, just go back to save your knocked out friend... Don't run to the nearest phone to call the police and get help... Plus, if you managed to escape the bed with your mouth, why not try that earlier?!
...If you are able to attack the mad doctor and stab him twice on the feet and leg, just bite him a little of his neck off, don't kill him or something...
...If you are a police and you are in the house of some guy with an amazing career on medicine but that it's suspect of being involved on the disappearance of several people and plus is acting crazy besides you, just drink from the water he offered you...
...If you hear some gunshots on the house where you just found 3 persons connected to each other by the ass, just run like crazy searching for your partner... Don't go slow or with some care...
Feel free to continue... :D
P.S. - I actually enjoyed the movie despite all it's flaws...