He had missed his last seven shots overall. He had clanged his last six 3-pointers. And he wasn’t looking good doing it — a 35-year-old man coming up short as the Celtics and Nuggets trudged into triple overtime. So, of course, Jason Terry stepped up and drilled the trifecta that provided the winning points in the Shamrocks’ seventh straight victory, a 118-114 decision at the Garden over the Denver Nuggets. Of course. Makes perfect sense. To Jason Terry. “Well,” he said later, “shooters shoot.” A minute later, with the Celts up two after a Danilo Gallinari free throw and a missed jumper by Kevin Garnett, Terry found himself on Andre Miller’s hip nearing the low block on the right side. It was the situation the Nuggets wanted. “I didn’t like our odds,” said coach Doc Rivers, praising Miller’s talent and craftiness. So, of course, the allegedly porous Terry knocked the ball away from Miller for his third steal of the game. Of course. Who else would you want on the defensive line with a minute and a half left? On a night when Paul Pierce went for a triple-double and got the Celts to the third OT with a contested fallaway trey and Garnett went for 20 points and 14 rebounds and Jeff Green made several key plays and others were just as timely, it was Terry who most came through in the last of many crunch times. The string of missed shots didn’t matter during a critical timeout. “Jason was in the huddle like, ‘P, we’re missing some wide-open looks,’ ” said Pierce. “Then he was telling me, ‘I’m making this next one.’