mechanics question
 

Tough mechanics, not a rule Q. 2 umps.

Runners on 2nd & 3rd, fly to left, R1 tags and starts home. Throw is immediate to F2, R1 retreats, F2 chasing.
PU hustling alongside F2, watching for tag, yells "I have tag", BU nearby.
Just before reaching 3rd, R1 drifts into fair, F2 swivels body blocking PU view; both still moving.
PU yells "BU’s name, yours".
Then R1 dives into 3rd as F2 attempts/applies tag; both now on ground. PU still blocked.
BU close to play, 90 degree to baseline, calls R1 safe as R1 beat tag to base.

Comments ?
USA SB or NFHS

If you deviate, communicate.

Sounds like an experienced crew that has worked together before.

Is there a better way to communicate that? Might the runner interpret that as, "That umpire saw a tag"?

I guess there are possible misunderstandings. The runner could think the PU meant tagged out, or maybe that she tagged up properly.
Either way, good point.
I would prefer "I have outside" or "I have home".

I wonder whether the PU had a chance to adjust to UV (unobstructed view).

BU close to play, 90 degree to baseline, calls R1 safe as R1 beat tag to base.

Same for BU, was there a chance to get perpendicular to runner path instead of baseline.

Kinda a no man's land situation. I would treat it like rundown scenario with PU drifting towards home and BU taking 3rd . BU should announce he has 3B.