thank you, its safe to say this is a rather rare occurrence. happens about once evry 20 minuts. thinking it might be related to lured pokemon. but got no solid proof yet. eyeballing bot like a hawk as we speak , wil post more once i get more info
found out that this happens when pokemon fled and got catcht on the rebound the pokemon in questions has a chance of its CP geting read as 0 once this happens and its that pokemon that gets traded away. minor bug good hopes of this geting fixed
edit , poster below me confirms my observation ! mistery solved