Basically the rebooted "backstep" which got changed into the escape skill, is bugged so it randomly doesn't go on cooldown. Sometimes even going off cooldown.
Had to trim the video a bit because it actually wasn't too easy to get it on record since its completely random and isn't affected by what you're getting hit by/pressing while doing it (because I basically stood there pressing E in intervals).
Happens in Arena and Spar but I'm not sure if it happens in PvE.
Here are some videos of it happening: