Yea I have no idea, I was jumping a lot like that today.  I've spammed jump a lot in that server and in the scrim server and this hasn't happened to me.  I also play on an SM server which has the same anticheat as you guys have with sv_pure 2, etc and have had no problem.  Again, I only jumped about 5 times before it ban me and I was jumping from heaven - roof - ground so I have no idea how it would calculate me jumping on the very exact frame.  I find it funny, if anything. 

Do you know if there's a support forum for that violation plugin you have on the server?  If so, I'd like to see if this has happened before.