Sorry for the delay, I forgot whether I posted this question on Flickr or here. Wow, so yes...this was something I had never heard of before, but apparently can happen in low-humidity cold weather and both of the times it happened, very different situations but both times below 40F, one time at quite high altitude (thin air). This issue had never, ever occurred to me before! So just...always be careful to wind film slowly, then? That should prevent this issue? I must have just been lucky to not go to fast at other cold/high altitude times.
Um...I've now come across a new issue, yet another bit of unfortunate damage has happened that I've also never seen before, will make a new post. Thanks a lot for the answers!