Ok, I appreciate the recommendation - I'll look into that.
I wouldn't say it really got much of a tug. All I did was tilt my neck to stretch and then suddenly my right sound was gone; obviously it caught on something... It's possible they got a few slight tugs before that too though - that cylindrical plastic bit where the two cables join is quite prone to catching on things for me. However, I do take care with them: I have a stand which I always rest them on, I make sure the cord doesn't fall under my chair wheels and I handle them quite carefully - obviously that wasn't enough though. But for this to happen, they seem quite delicate to me.
Yeah I can't say I'm a fan of the cables and their attachment at all. I had them coming loose fairly often until I finally took a tool to them to tighten them (which I didn't want to do tbh - ended up scratching the phones a bit ).