Yes, another thread about Assists... I shoot someone and then a teammate finishes him off, and I DON'T GET AN ASSIST, WTF IS THIS!?

Maybe you missed him.
One time I shot one guy around 40 rounds in the body (I thought). Then he killed me. Then I saw in Kill-Cam that I missed him by 5 to 10 centimeters.

Could happened to you, too.

No I got that white crosshair thing that pops up when you score a hit