Yes it can't be but I think this isn't such a big problem
Death evade is not such a big problem? Ok consider it not a big problem but what will you do if you are chasing a player and he death evades and you wont be able to gain the evade kill with hydra? Probably you will cry and will make it a big issue so YES it is a problem. Btw I still want your justification why it is not a big problem so my fingers are crossed on that.
On topic: So there's no possible fix on that? Well I think is, disable reclassing or duel commands when opposite team's hydra is over certain player's head or under his radar range and he wont be able to evade death by any means except for suicide or getting killed so I think this will make things good.