Glad that you didn't hurt yourself, David. I'm a new bandsaw owner, so I was watching a few videos on them. In one the guy was showing what can happen cutting a piece of plastic pipe. You had a similar problem. The blade pushes your work down, so when the material is square everything is quite safe. When you're cutting a round part, especially near the beginning or end of the cut, the downward force wants to spin your part. I think a V shaped sled might be better, or at least a block under the front of your work too, but I think I'd rather stay further away from the blade anyway.
Sent from my Hallicrafters S-40 using morse code.