[MrBasse]

How long is that piece that was being cut and which way was it being cut? Was it cutting the full width of the tube?

I don't think that the blade failed causing the aluminum to bend and bind, I think that piece is just too small to cut with adequate clamping force. The margin of safety on a miter saw is 4", I don't see how anyone's hands could have been clear of that margin. When the aluminum moved or twisted it snagged the tooth and when the material hit the fence the tooth snapped off. I have lost a tooth on a blade before and didn't have a catastrophic failure like that. I'd be curious as to the full details of what happened and exactly how the scenario unfolded.

Glad everyone is okay, stay safe out there!