I just got a bloodthirsty medal with the ballista only and it doesn't show it in the challenge for the skull camo. It's the third time it happens to me with the ballista. I'm still trying to get my gold camo because of this issue and it's just pissing me off.
That doesn't affect it, I've done that multiple times and still gotten the blodthirsty challenges done
Then you must have had 6-7 kills to earn that bloodthirsty, if you got a nade/c4/betty/claymore kill during that run, correct?