I've not gotten one of those, but I see where the possibility lies in either not locking the bolt ALL the way back instead of resting on the follower, trying to single load, or playing around with an empty one. You do need to be aware of what you are doing.
Both of mine need a push on the op-rod handle when a new clip is charged.
I imagine there is some very real damage incurred when the bolt bites the thumb.
They do make a device that keeps the bolt open after loading, but it also stops ejection of the clip. You have to load and then retract the op-rod slightly, ala M14. That may be handy for hunting with the M1.
