I think the obvious thing to do is report the mistake to the hotel and let them straighten it out.
Chances(as previous posters have mentioned) are the person missing the points has already complained about not recieving them or doesn't even notice he missing them. Believe it or not there are an awful lot of people out there that don't pay a whole lot of attention to points/miles. I know some of the sales guys at work who spend upwards of 200 nights a year in hotels don't have a clue how many points they have or even how many are earned per stay.

As for comparing it to finding 200.00 in your checking account thats just silly.