Should I have called it?

[Rachel]

R1 on 2nd. Ground ball to short. BR safe on a close call at 1st.
R1 rounds 3rd (too far) and attempts to get back to 3rd. 3rd baseman straddles the line and in my opinion is obstructing prior to receiving the ball and tagging out the runner. BU calls "tag-out".

I think I should have called the obstruction from the plate but I said nothing. BU discusses call with the offensive coach who did not ask for the BU to get help. I think I might have kicked this.

Do I call it right away? (am I jumping on my partners call?)

Do I wait to call it when asked for help? (that would look bad)

Is this the PU's call because it is the lead runner? (although this was a runner returning to 3rd and BU was at a 90 on the call)

The right call was obstruction and it did not get called. Let's get some opinions please.