Credit: Jonathan Leibson/Getty Images for Chrysalis Photo: Cory Monteith at the Chrysalis Butterfly Ball in Los Angeles on June 8, 2013

The world may never know exactly what Cory Monteith was doing before his tragic death on July 13, but the actor's friend and acting coach Andrew McIlroy is giving us a glimpse into that night.

Andrew says that the three friends Cory was spending time with the evening of July 12 — before Cory went back to his hotel room where he was found hours later — were actually positive influences in his life.

"They weren't strangers, they weren't bad guys. They were longtime sober friends. Cory knew them maybe 10 years," Andrew said. "Essentially, he had spent time with [them] as sober people. They were not using with him [that night]. There was no double life up here."

And to add to the tragedy, Andrew was supposed to have breakfast with Cory the morning he passed away. "He was fine, that's what's so awful," Andrew said of how the three friends described Cory when they were hanging out the night before. "The vigilance against using is nuts. If I or anyone understood the mindset nobody would ever slip."

Sadly, the last time Andrew saw Cory was a few weeks before he passed. "He was just recently out of rehab and he was good," Andrew said. "He was happy to be breathing fresh air and putting in full days and being active."

Source: People