Sounds like someone let you take time off when they really couldn't afford it, and you took the hit for it. It's a bad communication of expectations.

Someone up top probably said they wanted something done yesterday, and all your department had to say was that one of the key players was on vacation. They then assumed you should have known not to take vacation during this particular project.

Being that it's your brothers wedding, you really had to be there, but many businesses don't care about little details like that at the upper levels. They only see the bottom line, and whoever contributes to it.