BV untargetable in Praetor Sinclair's 2nd mission?

[darkgob]

Is BV meant to not be targetable at all when you first meet them in Praetor Sinclair's second mission?  Part of me vaguely remembers that being a thing from live but I might also be making that up, I don't recall.  The wiki doesn't say anything about it which seems weird if it's working as intended.  Defeating the Resistance ambushes ended the mission so I assume defeating BV was not a mission requirement, but usually in these cases you can actually fight the named boss and get them down to like 1/10 HP before they teleport away or something.  Even cone damage did nothing -- no dodge, no miss, no untouchable status, just nothing.