It happened to my Northface light weight pants at Tuolumne Meadows (3 days into JMT). Continued the rest of JMT with my rain jkt pulled fully in front! Then the belt button gave away at Reds Meadow. So forced to use the spare tent rope as my belt. At one point my back pack was holding my pants! Good incentive to finish JMT fast!
Northface did repair all the zippers and belt free of charge (looks like they have life time warranty on the pants (per REI) and now they are ready for HST!
Sorry to digress!
