Bernard Foley's last minute penalty secured the Waratahs their maiden title 33-32 on Saturday in Sydney and extended the Crusaders wait for their eighth to at least an eighth year.
Blackadder said he would have liked another look at referee Craig Joubert's fateful decision.
"It was 50-50 I thought, it could have gone either way," Blackadder said.
"It comes down to those moments doesn't it? There was nothing between the sides.
"I was really proud of the way our guys fought back.
"NSW have been the best team all season and they showed that tonight at the end didn't they, so that's a credit to them.
"They should be proud of their season."
While the Crusaders seven titles are still four more than the next best team, the New Zealanders have stumbled in recent times.
They have made the semi-finals every year under Blackadder since their last title in 2008, but four semi-final defeats and final losses away to the Reds and Waratahs have left them unfulfilled.
Captain Kieran Read was proud the fightback after they trailed 14-0, but couldn't hide his hurt and disappointment.
"We're absolutely gutted," Read said.
Blackadder won three titles as a player, but has yet to taste victory as a coach.
"Coming second is not much fun, I can tell you that," Blackadder said.
Playmaker Dan Carter suffered a badly corked thigh.
"He tried to run it off, but he couldn't quite get there, which is disappointing, at least he had a crack, so he's pretty sore," the coach said.
"It wasn't great losing him so early, but that's just life.
"I thought the guys that went out there did a pretty good job and Sladey (five-eighth Colin Slade) stepped up and kicked the goals that he needed to and Tom Taylor ran bloody well.
"But you don't like to lose those influential players."
