Multi-Hit Finishers with Slow Melees Can Cause Loss of Stealth Multiplier

[ChaoticLizard]

I was playing and going through Adaro, Sedna, when I was trying to get stealth finishers with my venka prime. However, sometimes the finisher would be excrutiatingly slow, but also it would cause the enemy to wake up (I had put it to sleep with Equinox's rest) and cause me to lose the stealth multiplier even though the enemy was in my finisher the entire time. Shouldn't it be that they can't cause you to lose your stealth multiplier if they are caught in a finisher?