But Arnold still stated his frustration with Glory's equaliser at Bluetongue Stadium, after replays appeared to show Billy Mehmet in an offside position before squaring the ball for Shane Smeltz to score.
Only minutes earlier, Adam Kwasnik had put the Mariners ahead with a simple finish at the back post.
And despite several opportunities and a missed penalty in regular time from Patrick Zwaanswijk, Central Coast were unable to capitalise on their dominance. The scores finished 1-1, with the Mariners losing the subsequent shootout 5-3.
Arnold acknowledged his side failed to kill off the game but insisted the Premiers' Plate was a greater achievement, playing down the significance of finals football.
"The performance was great but we didn't take our chances. It should never have gone to extra time. We missed five one-on-ones and a penalty," Arnold said.
"That's why I'm a traditionalist. That's why I look at the Premiership Plate with more value than the trophy for winning the grand final. Finals games are lotteries. It gets down to who performs best on the night and things you can't control, like decisions.
"That's two in two weeks and in the last finals series it was three. Maybe I should go to a big club where you get the big decisions?
"The players are devastated. That's the thing that hurts the most, when you keep getting bad decisions. They're always asking, 'Why'?"
Arnold quickly clarified his 'big club' comment and instead focused on the mid-season departures of two key players.
"The loss of Matty Simon and Rostyn Griffiths... our form over the last ten weeks has been good but we probably haven't played the way we wanted to play. Losing the heart and soul of your team has hurt us quite badly," he said.
"John Hutchinson has been doing a fantastic job [in Griffiths' position] but we've missed Matty's goals and his work rate up front. It's disappointing that you build a team at the start of the season to try to be successful and then you have two of your best players sold and that makes things difficult."Follow Sacha Pisani on