Has anyone used a Block/Event room to verify a BRG? I could BRG this one through either Hilton or Expedia, but don't see rules against it in their policies?

I am attending an event (Public) in April in Boston.
The event did purchase blocks of room, which are available to the public at a discount (for reference: http://east.paxsite.com/hotels.php).

The purchase process does not require any confirmation of event attendance, nor any rules that you must attend the event (with the exception of no reselling reservations), so in essence, anyone could book a room at this rate.

I'd love to actually book my room directly through Hilton but BRG it down to this event rate (even if I didn't get the extra $50, it'd be worth it to get my points and card priveleges)...

Thoughts?