Elbow out of primary

[wyo96]

BV, 3 man crew. Game is in control, 3 qtr, A up by 15.

I was L, ball is high on C's side, A1 has used his dribble and is under pressure from B1.
A1 is moving his torso to keep the ball away, and in my opionion, "not exceessily" swing his elbows.

As I am looking thru the lane from L to C, I see B1 flinch and hold his face as A1 elbows apprears to contact B1. C got straightlined and said after the game he did not see the contact.

From L, I am 100% sure there was "contact" but cannot tell if it was just a brush by A1 and B1 over reacted, or if it was solid. Way out of my area, but a possible elbow to the face. I did not do anything, but got to thinking afterword, that a whistle may have been correct. Do you reach that far to get it? Non-basketball play? Again, not excessive swinging from my angle.

Should C have a whistle without seeing the contact?

Thoughts?