Bug with take back and "en passant"

Hi,
I was able to perform the "en passant" capture but I made a mouse mistake. Then I asked for a take back, which my opponent accepted, but I wasn't able to play the "en passant" anymore. So I think there is a bug there.
And it costed me the victory, so I'm very mad at the developer and I hope I'll get some kind of compensation.*

Thanks a lot!

* just kidding of course ;)

got it, will fix