First of all, all of you guys are wrong. It IS possible to get a hitmarker with a knife/ throwing knife. It is VERY rare for this to happen since you need to knife/ hit them with throwing knife at the exact same time that THEY are going into last stand, as you can see in the video, the guy that he got the hitmarker with was being shot by another guy which made him go into last stand and creating the hitmarker that we can see in the video. And second there is no scavenger backpack in the video. This happens in both Call of duty 4 and modern warfare 2. Not sure about W@W.
And for all you non believers here is a video proving it:
COD4:
[ame=
https://www.youtube.com/watch?v=_3aMuRMN4sI]YouTube - assist with a knife[/ame]
MW2:
[ame=
https://www.youtube.com/watch?v=qg_OLCeO2iQ]YouTube - MW2 knife assist[/ame]
+REP if this helped