When to over-rule?

[Rev.Ref63]

I was working two-man last night with a veteran (23 years) official in Missouri. He was lead, he called a foul on the baseline. I thought it was a shooting foul so I instructed the players to line up. After reporting the foul, he said it was non-shooting.

The coach questioned whether or not his player was shooting so he (my partner) came to me and said, "I had the foul on the floor. What did you see?" I simply stated, "I'm not going to change your call," and I put the ball into play without further argument from the coach.

From my angle, it looked like the foul occured during the act of shooting, but I was out in the trail position.

Question:
1. Should I have over-ruled him since he asked, or did I do the right thing?

2. When is it proper to over-rule?