Hi quickdash,
Since the At-home GMAT is a relatively new product offering, there isn't a lot of 'precedent' for how these types of situations will be interpreted by GMAC. While I certainly believe that you left the Exam simply to go to the bathroom (and not to 'cheat' - for example, to look up a grammar rule for an SC or ask another person for help/advice) - there's no way to prove that those things did not happen. I suspect that some consideration will be given to how far into the Verbal section you were when you left the room - and potentially how well you were performing up to that point in the Exam - but from a functional standpoint, you broke one of the 'rules' of the At-home GMAT so GMAC has to decide how strict it's going to be about that rule. Since the typical waiting period for many GMATers has been 3-7 days, we probably won't know until then (or perhaps longer) what the overall results (both in your Score and whether GMAC 'flags' it or not). I imagine many people would be interested in hearing how this ends up, so I hope that you'll post back here once you hear word.
GMAT assassins aren't born, they're made,
Rich