They were baying for blood in the usually polite precincts of Avery Fisher Hall.

The unmistakably jarring sound of an iPhone marimba ring interrupted the soft and spiritual final measures of Mahler’s Symphony No. 9 at the New York Philharmonic on Tuesday night. The conductor, Alan Gilbert, did something almost unheard-of in a concert hall: He stopped the performance. But the ringing kept on going, prompting increasingly angry shouts in the audience directed at the malefactor.

After words from Mr. Gilbert, and what seemed like weeks, the cellphone owner finally silenced his device. After the audience cheered, the concert resumed. Internet vitriol ensued.

But no one, it seems, felt worse than the culprit, who agreed to an interview on Thursday on condition that he not be identified — for obvious reasons.

“You can imagine how devastating it is to know you had a hand in that,” said the man, who described himself as a business executive between 60 and 70 who runs two companies. “It’s horrible, horrible.” The man said he had not slept in two days.