Right, this happened to me twice already, not always will be the case, but it does happen.
I’m chaseing this completly lone FT guy next to a big warehouse (wtf were you thinking dude?!?!) obviously closeing the gap and killing him. Rest of FT is still farr away (so I thought) so I do a long claim on the poor bastard. FT suddenly show up and stuff me with led, so i cancel the claim and run away - I did not even manage to stab him once, his skull is not on my belt yet I have his nick name on the right hand side of the screen above “CLAIMED”.
As I said - second time this happend. Under some factors you can just cancel the long claim anim but still score it as a claim.