Congrats on the drivers.
I don't think it's a big deal. Sounds like many people involved with the school were in the raffle, and many others won. Generally in a contest, anyone affiliated with the organization, as well as their immediate family members would be excluded from entry. I know that this is not always the case, but in larger contests, such as on line giveaways from larger companies, it is usually in the fine print. However, raffles are generally much more relaxed. I've entered a ton of raffles where somebody working for the organization, or even running it, had won something. It's for a good cause, so who cares?