That sucks!!!

Some bosses are really crappy, and believe me I've had my share!
I don't know what his company policy is/was, but for some companies you have to put in a request for vacation time, and someone appropriate has to approve it before you can take off. If Dwayne put in his request and it was approved, I wouldn't think that it is legal to fire him for it!!!
Something like that happened to my aunt - her boss was gone on the day she put in her request so the manager in charge of her dept that day approved it and she almost got fired for taking her approved vacation!
FYI, they are never supposed to ask WHY you want vacation time, one boss I had got in trouble for that. he also always asked WHY you wanted to go home sick, which they are not allowed to do either.