Was there an ongoing case before them?
Was the meeting ex parte?
Who called the meeting?
Was there precedent for the meeting?
How did the case that was before them work out for the
litigant who was not at the ex parte meeting?
Q.E.D.
Yes, there was an ongoing case.
Was the meeting ex parte?
Meetings are not ex parte, decisions are ex parte. You have not demonstrated that the court case was even discussed, much less decided at that time. Your ex parte argument fails.
Who called the meeting?
John Roberts called the meeting.
Was there precedent for the meeting?
Yes, there is precedent. Reagan and Clinton both visited prior to the inauguration. GW and Cheney deferred.
How did the case that was before them work out for the litigant who was not at the ex parte meeting?
You are assuming facts not in evidence, that the case was decided at the meeting.
Q.E.D.
Not when 4 of your 5 pillars turn out to be mush.
It's not considered an ex parte meeting if they didn't discuss the case. See the link above to Scalia's opinion on his hunting trip with Cheney.
Who called the meeting?
Chief Justice Roberts.
Was there precedent for the meeting?
Yes-- both Reagan and Clinton met with the Supreme Court shortly before they were sworn in.