Continuity mistake: When Dan and Allison are in bed and they finish kissing, you can see their bare chests and shoulders and the sheet is around their waist. In the next shot of them, the sheet is over Dan's shoulder and when he rolls over, the sheet is covering Allison's chest, before she pulls it up.
Character mistake: During the surgery, one of the surgeons says to give the patient 25 cc's of cyatril. Then one says make it 35 cc's. 35 cc's (or 35 mL) is a full large syringe. The other doctor uses what looks like a 3 mL syringe and it's only partly filled. It seems the surgeons wanted 0.35 cc's.