Mr Collins said the coaching team was penalised after they badgered the referee on calls to the point where it turned to verbal abuse.
Both clubs have been praised for their behaviour since the incidents.
Mr Collins said the Hora Hora incident was serious enough to warrant a hearing.
"We've got to protect the officials. They do a great and vital job for rugby. If this continues we won't see referees coming into the game going forward."
The NRU did not supply a referee for the next fixture against Kamo as they couldn't guarantee the referee's safety, giving Kamo the default win.
Since then the referees have been welcomed back with open arms by Hora Hora and have officiated their last two Bayleys Premier Reserve fixtures.
Northland Rugby Referees Association Incident Committee member Gavin Benney said the referee who took on the first match back against Western Sharks had nothing but positive experiences at the club.
"Hora Hora have taken it on board. Once the thing had been dealt with the referee said there was a complete change in attitude there," he said.
"The club met the referees, had Powerades waiting for them in the changing sheds and welcomed them before and after the match which is great to see."
The week before this incident a supporter at a Hora Hora rugby match was given a one week ban for confronting the referee in the clubrooms post match.
Hora Hora Rugby Club president Carl Milne said the situations had been dealt with at the club.
"We dealt with the individuals internally which was us being proactive more than anything," he said.
"We've got passionate supporters. We just had a quiet word amongst everyone involved and it's just unfortunate that we've had a couple of incidents over the last few weeks.
"It's been a remarkable improvement. The referees and the NRU are more than happy."
Mid Northern club captain Tim Williamson said the club was happy with how they were dealt with.
"Both issues have been dealt with within the club alongside the NRU. We certainly think the right outcomes have been met," he said.
Benney has also been heavily involved with junior rugby at Kensington Park, tasked with cleaning up the side-line behaviour of spectators.
"The improvement up there has been brilliant, in two years we've changed the culture" he said.
"We had two main initiatives up there. We roped off from the side of the field and we put coaches, managers and reserves behind the posts. We believe a lot of side-line abuse comes from hearing the coaches.
"We also reinforced that it is not okay to have a crack at the referee. I would give anyone a reminder of that if something happened."