Probably multi attack/assist attacks. If 86 uses his assist to hit Dooku, he will crit, Dooku will stealth, but then Dooku will still get hit by the second assist attack and make it appear as though the assister is targeting Dooku through stealth. Same thing could have happened with Nebit using his assist.
Then theres B2 who could've dispelled stealth, but then most of your sith dodged the dispel and Dooku was unstealthed but gained advantage and the presence of the advantage buff made it look like he was still stealthed because there was still a green buff over his head.
