sounds like what happened to me when I put htc one in my shirt pocket, caused by inadvertently pressing application buttons. Result skipping audio tracks, changing radio station etc.
Cure - press power button to turn screen off.
it was lack of FM radio on the G4 which was the deal breaker for me.
Regardless of how fantastic both phones are, this is important to me, but probably in a minority.
HTC One ordered, migrating from Samsung G2.