Opponent offered draw but then claims they didn't!!

My opponent offered a draw which I accepted but they then claim to have not offered a draw and are wondering how the draw offer happened!

I can't see how this would be possible and suspect my opponent has made an error in offering a draw in our game rather than in another they were playing..
Thanks for any thoughts.

This has come up several times since the new UI arrived, we usually hear from the person who knows they didn't offer the draw, yet the opponent received an offer. There may be a program bug.