It wasn't any one thing.
Though even one of the many things, given Dabo Swiinney's no-nonsense approach to discipline and 'culture,' would have been enough for Chad Kelly to have been shown the door.
Little did anyone suspect, however, that he'd marched out of the WestZone Monday afternoon, and later be dismissed from the Clemson football team and a denied chance at a promising football future - at Clemson, anyway.
Kelly had been moving toward this outcome for a while, and Clemson's coaches and Kelly's teammates had been bending over backwards to make it not so, even before he arrived on campus.
On a day that the athletic department honored its best and brightest during the second annual 'Clemmys,' Swinney was forced to make the toughest decision any coach ever faces.
And he didn't even have a choice.
In his statement released by the university on Monday, Swinney referred to a 'pattern of behavior' starkly at odds with everything the Clemson football program stands for.
If there's any question about the 'standard,' ask Garry Peters, Corey Crawford, Shaq Lawson and David Beasley, who'll be on the sidelines on August 30 as the Tigers venture between the hedges and try to beat Georgia.
Why would Kelly think his situation would be handled any differently?
The problem was, Kelly acted without thinking, losing control - venting, verbally abusing first his coaches after an insignificant spring game decision, and later, according to reliable party, going ballistic after an relatively insignificant traffic incident in an apartment complex parking lot.
It wasn't the first such incident, only the last.
When he was called in Monday to give an account of his actions, Kelly, by all reliable accounts, exploded again, earning his escorted exit from the Clemson football program.
"Pattern of behavior" is the phrase that sums up Kelly's demise.
It may well have started in high school. He was suspended, after promising starts, from both his freshman and sophomore seasons from York County, Pennsylvania's Red Lion High - the dismissals never publicly explained, but handled, according to his former high school coach, "in house."
A year later, Kelly emerged as a transfer at Buffalo's St. Joseph's Collegiate Institute as one of the top-performing quarterbacks in New York high school football history. His family legacy - the nephew of NFL Hall of Fame quarterback Jim Kelly - coupled with his unprecedented statistics, made him a national recruiting target.
The Tigers' coaches made a decision to pursue Kelly, and he picked Clemson over Florida State in a tightly-contested recruiting battle.
As a Tiger, the first thing he chose to do was, figuratively, to spit in the face of his chief competitor at Clemson, Cole Stoudt, who had signed on with the Tigers with expectations of spending much of his career as Tajh Boyd's backup.
"Your (sic) on the bench for a reason. And i come soon! Just letting you know," Kelly tweeted in reference to Stoudt.
Stoudt responded: "I hate those that talk like their (sic) the s*** when they haven't done anything yet."
Later, during a visit by Kelly to campus, the two players made some semblance of peace.
Another incident occurred last fall, after Kelly had worked his way back from an ACL injury with near-miraculous speed, and onto the field as the Tigers' third-team quarterback.
With the game against The Citadel well in hand, Stoudt got his turn at the controls, and, at the end, Swinney handed the ball to senior walk-on Donny McElveen for a curtain-call.
Kelly was visibly upset that he didn't get to play, and he later confronted the coaches. He described the incident later during Clemson's preparations for the Orange Bowl.
“Y’all all know that I didn’t get in the Citadel game and I was very upset and emotional,” Kelly said. “I like to play football and that’s what everybody likes to do. Me and him (Chad Morris) and Coach Swinney kind of bumped heads a little bit. We sat down and talked for an hour and half and it really opened up my mind and got my mind right. I talked to my parents right after and I was like it’s a new beginning from here on out. I only have to deal with it for a month and a half longer until the quarterback job is wide open.”
Kelly competed well all spring, and about a week ago was asked if he felt had done enough to beat out Stoudt for the starting job. "Big time," he answered.
Saturday's Orange-White game told a different tale.
Stoudt appeared poised and in command of the offense, making the right reads, taking what the defense allowed, moving the chains, and hooking up with receivers for touchdowns.
Meanwhile, Kelly struggled. He threw a pair of interceptions into double-coverage, and grew frustrated as the first half progressed.
Near the end of the second quarter, on fourth-and-three near midfield, the coaches called for a punt. Kelly responded with a blow-up, and after a consultation among Swinney, Morris and Jeff Scott, Kelly was benched for the second half.
When the end came Monday, Twitter exploded, with fans and players weighing in on Swinney's decision and Kelly's demise.
Some of the comments took an ugly turn, along a 'good-riddance' theme.
"I want to bash him," someone tweeted.
At this point, Tiger offensive tackle Eric Mac Lain weighed in and reasserted a bit of reason and compassion into an all-around regrettable situation.
"What will that solve?" wrote Mac Lain. "He was still a Clemson Tiger...we should be encouraging him to make better choices 'n hope for the best."
Follow Kerry Capps on Twitter @oandwkc