He must have said 'bad primer' like three times, and each time immediately ejected the shell. If there had been a hangfire once the shell was ejected, that would have been no fun either. No safety can or hole nearby to kick the thing into. By the second time through he should have been checking the barrel instead of pounding on the FA.
When you're not being shot at, seems like a good time to take your time. Waste of a good rifle IMO.
One thing - if you indeed found a bullet lodged in the barrel, I assume you'd knock it back into the chamber from the muzzle with a dowel or cleaning rod? Maybe a .22 caliber delrin rod would be a good thing to have at the range.
What are the odds of having this happen without using 3 rounds and the FA to drive the squib deeper into the barrel so the sear/disconnector works (as he did?) I'm thinking even with cheap ammo you'll just go 'click', which I can deal with. Anyone here have a link to kabooms caused by 'factory' reloads? I remember hearing something about a company in GA...
ETA: Seems to me FTEs are the thing to watch for. If there's not enough power to eject the shell or even open the action, that should be a clear clue. I didn't see him check his brass. Takes just a sec to pop the action open (if you aren't on a 2-way range)