I wasn't there when he broke the stems, but knowing him, it was both.Was your chum overzealous in how long he heated the stems for, or how often he did it? Or both? I figure if I have 2 stems it's worth the gamble. I'm not worried about breakage through dropping them or anything (as I'm obsessively careful about things that can break in this way, being the clutz that I am), so figure if I lose one through torching it'll be a lesson learned (and hopefully a fun one).
Thanks for the reply
Give it a shot if you're curious, but just be careful to not overheat. Another problem with overheating while doing this is the risk of having your oil "run" down the stem only to find a new home in your bongwater where it's lost forever.
Good luck!