Nimoy wasn't involved in the incident. Whitney told him about it after the fact, and they were in the room together when the "executive" came by with a polished stone to apologize. That's why he knows the man's identity.
Didn't mean to imply otherwise.
I'm sorry, Harvey, you didn't imply that, but I came to the wrong conclusion. I've read the sample text available to the book on amazon and it explained very well that Mr. Nimoy is a caring man and she confided in him. Sorry I thought something else might have been the case.
Maybe this is too off the subject of the OP but I think a better demenstration of racial equality and breaking of stereotypes in Star Trek is in Court Martial when Commodore Stone was bossing Capt. Kirk around as his clear superior. But maybe that isn't dramatic enough.