Взято отсюда:
Probably you vanished within detection range & in front of the rogue. If you Vanish you remove Vendetta and increase your "stealth level", but if you're very close you can still be detected. Stealth detection lasts a couple seconds even if you immediately move away or even behind your enemy, so you probably remained visible briefly after running away, which got you killed.
I try to move away or gouge before Vanish to avoid small problems like getting a hunter mark after vanishing (which happens quite often, unfortunately).
Здесь говорится что ваниш сразу повышает стелс левел. но не снимает сам эффект вендеты.И если не отбежать от цели(не выбежать из просветилки охотника) есть шанс получить в ваниш марку охотника