King turning red

If I look back at a game and I check my opponent it glitches and my king turns red why is this?
Or is there something that I am missing?
Regards Nico

Link to the game/analysys and movenumber pls

Here is the link: http://en.lichess.org/3rgTU3iP/black#22

same thing happens to me

Is it a bug?

The wrong king is turning red for a second before the correct one, seems to happen for other games too.

Yes, I've had this too - it is entirely random - nothing to do with the game link (happens in most games) and it doesn't matter whether or not the king is in check

Nothing serious, just a small funny bug. I made a video of the "problem".

youtu.be/fL6gvTSbXfs

Will fix!