The word or a timeshare salesperson is worth about as much as that of a used car salesperson, maybe less across the industry. While DVC guides are pretty honest overall (compared to their non DVC counterparts), they do earn a living getting you to buy points. If this is the worst "lie" that they tell anyone, we're all in pretty good shape.
As for calling MS and being told it's ok to have 5 in a room in contradiction to the legal paperwork, I wouldn't think this would hold water either. I know that enforcement has been spotty and that people have not usually been turned away, however, that doesn't change the official rules. And as noted, some have been prevented from making reservations in violation of the occupancy limits.
One thing to think about with this type of situation is that if one contacts the official parties, there are 3 basic ways thing can go. One of those options is to move toward more hardline adherence to the rules.