The shooter fired at least 4 shots, so he’s got 2 left in the drum.
So is there a way to keep the thumb over the 2 live rounds when the drum is swung open , (so they don’t fall out ), while shaking out the 4 spent shells?
If so, then IDK why the shooter would take one shell out at a time , since he could theoretically dump all 4 spent shells in one quick shake while still holding the 2 live shells in chamber with his thumb.