You remember wrong maybe? That was Doug Free, last pre-seseaon, as rookie, holding up well against Dwight Freeny in one of the pre-season games. I am pretty sure it was Doug Free you might be thinking of, since McQuistan hasn't shown much so far. First year probably was better than this year. But I don' think he played LT for sure in place of Flozell. He might have played against 2nd or 3rd stringers though, which I am not positive about.
Nate says, problem with McQuistan seems to be, that he doesn't forget bad plays. He goes downhill once a bad play occurs, according to him.