An Even Number of Umpires Making the Call

[teebob21]

R1 on 3B, no outs. I am base umpire in C position. BR hits a soft grounder up the 1B line and it is fielded by F3. BR stops on baseline maybe 15-18 feet out of the batter's box (I am charging into the diamond). F3 throws to F2 who makes a late tag play on the scoring R1, ruled safe by my partner. At the same time as the throw from F3 to F2, BR steps back towards home. (NCAA 12.2.11)

Both my partner and I came up with Dead Ball at the same time. Since he was closer than me to the BR, and he is generally louder, he administered the call and I backed off. BR out, R1 goes back to 3B, no run scores. No one complained about anything and the game went on.

Here's my question: which umpire has primary coverage of the BR interference on that situation? Is it the base umpire (who has responsibility of the BR to 3B) or the plate umpire (who is closest)? CCA Manual isn't specific in this case, but does offer a general guideline that the umpire closest to OBS/INT makes the call. Did I step on his call?