For those that are commenting on the specifics of the coaching box and laying it out for coaches in pregame, I look at this as just an example of a type of behavior. It really could be anything, such as "Watch their center, she tends to throw a lot of elbows if you aren't watching." The intent here wasn't to obtain clarification of enforcement of a rule, it was to put the ref in a certain mindset with relation to the other bench.
Not appropriate, period. I don't know if anybody has done that in any of my games, but I have never had a ref do what you did. I like what you did in going to the other coach - it keeps everyone on the same level. And if you knew at the time (rather than after you left the conversation) that the first coach was working you, you could have told him that you would appreciate him asking for those type of clarifications when you have both coaches together. Tell him that's what you meant by "any questions." Tell him that any further discussion of this type will involve both coaches.
gfs23 - I am not a big coaching box fan, as long as coaches stay within limits. It should be enforced as needed not necessarily as written. You come on my side of the court or obstruct the table's view, it's a problem. If you wander far and wide to yell at officials, it's a problem. Otherwise, it's kind of hard to see