So not that this matters for any army I will play because I don't use Illic or Vindicare Assassins, but I was looking at the BRB which says the following:
"Precision Shots
If a model with this special rule rolls a 6 To Hit with a shooting weapon, that shot is a ‘Precision Shot’.

Wounds from Precision Shots are allocated against a model (or models) of your choice in
the target unit, as long as it is in range and line of sight of the firer, rather than following
the normal rules for Wound allocation. A character that has a Precision Shot Wound
allocated to it can still make a Look Out, Sir roll.

Note that Snap Shots and shots from weapons that scatter, or do not roll To Hit, can never
be Precision Shots."
This, in combination with the vindicare's (Illic has a similar one) rule

"Deadshot: All successful to hit rolls made by a Vindicare Assassin, excluding snap shots, have the precision shots special rule."

Theoretically, with the fact that his weapons are sniper weapons which already have precision shots, the clear RAI is that he picks where all his shots go, regardless of the to hit roll. But RAW, I'm not so sure. Thoughts?