I've been happily using standard shell holders in my puller for about 40 years. I've read the horror stories of a detonation while using common shell holders in a hammer puller. Can't say it's impossible but I don't see how it could be possibly be true as it has been described (or any other way) because the primer seating punch and its sleeve has to fully enter the largish center hole in a shell holder and that priming hole is big enough that I see no way any part of a properly seated primer can physically contact a shell holder during pulling.
I don't think a cartridge loosely held inside a hammer puller could/would detonate anyway. Yes, IF ignited, the powder would immediately burn enough to push the bullet out but that should immediately release the case pressure to near zero and the remaining powder would continue to "slowly" burn away, not explode. Meaning, IF it happened at all, it would be a fire hazard for a few seconds but not blow anyone's hands or head off!
Do as you wish, we're all responsible for our own work. I'm not going to stop pulling bullets with standard shell holders until I see believable evidence that a round has actually done what I've read so far; there has to be a lot left out of the stories (and disaster photos) I've seen.
>> It helps a LOT if we seat jacketed bullets just a few thou deeper before pulling. That will break the chemically bonded metal adherence between the bullet and case neck.