At what point...

[ODog]

Some people are just douches and life is too short. Block them. No apologies or explanation necessary. There are many officials and many games. Life will go on for you and for your assignor without you having to do a game with a blocked individual.

And you won't be missing out on anything, because any game this individual(s) does, you wouldn't want to have done with him anyway.

Block ... him.

If your assignor offers the option, take it. If there's a limit to the number of partners you can block, block right up to that limit. You can avoid A LOT of cringing, dread and train-wreck games with weak/obstinate/douche partners this way.

You'll enjoy your seasons a lot more knowing that you'll never get games with these people. Trust me.

[LRZ]

Don't let that guy get into your head to create that tension. If you can't block him, have confidence in your own abilities and call your game. Then, when he offers his post-game remarks, just nod politely.