how would you fix this?

[Paul L]

The proper foul mechanic is raising both arms in the air and verbalizing "foul". Right? BU did not use either mechanic, just pointed with his left arm, presumedly toward foul territory. If memory serves, the foul mechanic was changed many years ago precisely to avoid accidental foul calls.
The proper fair mechanic is pointing towards fair territory and verbalizing nothing. This is what BU did, except for the accidental point in the wrong direction. So why is BR entitled to think foul was called?
Well, I guess I know the answer to that question. If the commonly understood foul signal caused BR to stop running, then BU has to eat the foul call.
But I was surprised no one mentioned the wrong foul signal. Is pointing foul, rather than raising both arms, the proper signal anywhere?