I'd actually disagree on that one. My experience with med school pre-req TA's is they either don't really give a crap and give everyone A's or they are extremely biased in favor of/against certain people in the class. My lab partner and I were once on the receiving end of a TA who...uh...appeared to have a striking preference for the sorority girls in our lab. I was in another group where the TA decided to start hacking people's grades for no reason. I'll never forget being docked 5 points for "sentence too long" on a sentence that barely spanned 2 lines. Some people got their grades mutilated, while others didn't. (The course director didn't do anything about it, in case anyone is curious.)
One thing that hasn't been mentioned yet is that since you received separate grades for the lab and class, med schools won't give you credit for that lab. You'll need to retake it and score at least a C.