It is somewhat presumptious to assume that a Rav, who it seems was not playing a pivotal role such as mesader kidushin or the like or the like must show up at your simcha. SHowing up for five minutes does not mean just five minutes of his time. It means the time going and coming, there may prepearation time coming. There are a million other things that he is involved in. Did you offer to send a driver to wait for him? Did he say he was coming?
Is this the Rov that you ask your shailos to?
You said he was someone you had a connection with. You do not expect every other person you have had a connection with to come to your simcha nor do you probably even invite all such people to your simcha.
Do you go to every simcha you are invited to?
Why do you think that you have the right to demand of his valuable time?
There are rabbonim who do not go to simchas because otherwise they would not have any time at all to do what they need. Let alone any personal time.
It seems the one lacking midos is the one who is demanding the Rov to show.