Council Chairman Rex Graham said he would have his say after Wilson left the room, despite not having a quorum.
He said originally he was in favour of delaying the new minimum flow regime, but had since changed his mind following community consultation.
Councillor Tom Belford said the action opened a can of worms.
He said if that was the way the regional council was going to conduct governance, he would absent himself from every meeting.
"A clever move, yeah, good governance, bulls...."
He said it was a mistake of the meetings' co-chairs to accept the walk out, and felt they should have a conversation with Wilson.
Graham, however, did not believe having a conversation with Wilson about governance was going to bring him back into the room.
Without a quorum, the committee had two options, either agree to defer the decision, bring Wilson back into the meeting and continue with the rest of the agenda, or cancel the meeting.
"I'm not going to be blackmailed by him," Graham said, and cancelled the meeting.
The committee will discuss the issue at the next meeting in two months' time.