Then it would be back to New Zealand to prepare for the All Blacks' first two Tests of the 2020 season against Wales.
Mooar said it had been important to him to commit until the end of the season to finish what had been started and to leave the side in a position where it was ready to explode and advance.
"You can't control the timing of the opportunities. As a Kiwi lad you want to play for the All Blacks. I was always available but never picked," walesonline.co.uk reported.
"In terms of coaching, it is the pinnacle to represent your country and the opportunity to do that has a magnificent pull to it.
"It was a trying time to work through that and knowing which way you were going to go. You balance that with doing something you love here at the Scarlets," he said.
Mooar said the chance came about after a conversation with new All Blacks coach Ian Foster. His first reaction upon getting a phone call was to ask Foster if he had the right number?
"I was humbled to be part of the conversation and to be in the position of having two magnificent opportunities was just humbling," Mooar said.
"We [he and Foster] have collaborated for a long time and have a good relationship and exchange ideas regardless of who we are coaching.
"He was putting his team together and thought I can add to that. He rings up and says, 'I know you are in a role that you are loving and we want to talk about another one'.
"We talked through that and things rolled from there. It is grown adults having adult conversations and however difficult they might be it is important to be honest and empathetic and maintain integrity," he said.
Mooar said he was keen to see that what had been started with the Scarlets since taking the position from fellow Kiwi and new Wales coach Wayne Pivac would continue. He was willing to be part of the conversation involved in finding a successor and he believed club administrators were well down the road to the future.
"It is a happy group and things have been started that are positive and leading on from the great work that Wayne did in the last four years or so," he said.