Nothing new here really......

MA props are known to throw blades....thats why APC props should be used.
I've seen several blades tossed over the years and they have always been MA.

The last one I saw was a local friend running up a 3 blade on the ground just before takeoff.
One blade came off, the engine ripped the entire nose off the airplane and the fish head went zooming over the clubhouse, hit someone's mother in law in the tail feathers, then went on down the parking lot and the engine needle valve got stuck in the sidewall tire of an Edsel.

Fortunately, no one was hurt....
Spend more money for a good prop and this will never happen again.