Grounds For Disqualifying An Arbitrator

Background

Imagine the following situation: at the old coffee shop located at the hallways of the Court, two people are talking, one is an arbitrator in a famous case and the other is representing a big client in that same case. The two have a deep and long-standing acquaintance from their academic days. Among the exchange of words, the arbitrator asks his friend's advice related to a different case being filed against him.

Assuming that you sat for a moment on the judging bench, would you consider disqualifying the arbitrator from ruling in the aforementioned case, or not? Or maybe disqualifying the attorney who gave the counselling (since maybe he hoped to get something in return for his advice)? And if the relations described were between a judge and an attorney, would your decision remain unchanged?