The problem is on both tapes shot that day. The footage is definitely underexposed but not to the degree that you can't see what's going on. It can be lightened up in FCP but that just increases the problem of the noise. The noise is primarily in the dark areas. Yes the monitor was used as a reference for the exposure and is part of the reason why the footage was underexposed. Now why there is an excessive amount of grain/noise can't be determined.