Administrators must either provide an adequate explanation for Joe Paterno's dismissal or risk the financial and spiritual upheaval unhappy alumni can create.
For many among Penn State's several hundred thousand graduates, the firing of the Nittany Lions' legendary ex-coach remains the unmistakable focal point of the shock and discontent that has exploded since Jerry Sandusky's Nov. 5 arrest on child-molestation charges.
Over and over again on Thursday, in the same relentless way Paterno's offenses liked to hammer away at opponents' weaknesses, these loyalists asked Paterno-related questions of Erickson; of each other; even of Franco Harris, the former football star who was there to add heft to his fellow grads' displeasure.
Why did the trustees rush to judgment and fire Paterno? What, if anything, did they know? And since, in the alums' view anyway, there's no evidence against Paterno, why hasn't the university begun the process of restoring his - and, by extension, its own - reputation?
They were mad, discouraged, and undoubtedly a little embarrassed at how their school had reacted to this unimaginable scandal, how it had failed to defend itself against media critics, how so many momentous decisions had been made behind closed doors.
But Penn State's worst sin, in their blue-and-white view, was the hasty and heartless sacrifice of Paterno, the most beloved and influential figure in university history.
"The only reason they did it," one middle-aged woman in a Penn State football jersey said to a companion, "was because the media kept screaming that they had to. The trustees should all resign. But only after they apologize to Joe."
As Erickson's guarded performance implied, that's not as easy as it sounds.
There are few simple answers in a scandal rife with legal complexities and human sensitivities. And the besieged trustees, wary of a potential avalanche of lawsuits, aren't likely to publicly defend their unanimous Nov. 9 decision.
In fact, the 32-member board's tepidly worded statement on the subject, issued just hours before Erickson's appearance, seemed to do more to inflame the situation than resolve it.
"Do they really think we're this stupid?" asked one graduate as he read the statement on his iPhone.
Whatever Paterno's culpability in the Sandusky affair might be - and, with little to counter their zealous defense, his supporters continue to insist it's zero - Thursday's session made it clear that Penn State must find a way to appease this increasingly large and loud faction.
"In discussing Joe's situation, the word I heard from almost everyone I talked to [Thursday] was 'disrespected,' " said Anthony Lubrano, the Chester County graduate and donor responsible for Harris' appearance and an alternative Q&A session in Valley Forge Thursday. "These people deserve answers. They're Penn State graduates."
They're also the ones whose donations, tuition payments, and ticket purchases help support a university with ever-diminishing state funding.
Penn State is in the midst of a $2 billion capital campaign, and the athletic department relies on football-generated donations to pay its bills. While Erickson has insisted the scandal has not negatively impacted these efforts, it's probably too soon to tell.
"At this point, no one can really say what kind of financial effect it might have," said Lubrano, a financial analyst who has given millions to athletics. "I'm not sure I believe the administration when it says there's been little effect. Some of the numbers they based those comments on, I believe, were from before this whole episode began.
"But there's no question it's a volatile situation. On the one hand, none of us [donors] wants to hurt our university. But on the other, we want to let people know we're unhappy."
So how can Penn State still the discontent?
Even if the various ongoing investigations clear him completely, Paterno's not going to get his job back. He's 85 and undergoing chemotherapy for lung cancer. And besides, Bill O'Brien was just signed to replace him - for a lot more money, by the way, than the old coach ever earned.
As for tributes for Paterno, Erickson satisfied no one when he told the audience that as soon as time permitted he and the administration would plan one. A president who in the two-plus months since Paterno's dismissal has yet to even speak with the coach had little credibility with this audience.
"Nobody from Penn State has called Joe, except for Bill O'Brien and a fund-raising official who needed to resolve some preexisting issue," noted Lubrano, who visited the former coach last week.
Would a Nittany Lion Inn banquet appease the bloodthirsty grads? How about a halftime ceremony? Or a sweeter retirement package - something now being negotiated?
Penn State could, as Lubrano and others have suggested, get down on a knee and publicly apologize. If it's too fulsome, however, it could be viewed, by Paterno's attorneys certainly, as an acknowledgment that the university erred in firing him.
"There's always the risk that the damages done to the Paternos might result in litigation," Lubrano said. "But I know the kind of people Joe and Sue are. If Penn State would merely extend them an olive branch, I'm certain they would welcome them.
"Joe might do a lot of barking, but he's got a gigantic heart. I can virtually guarantee that he would put an arm around whoever it was and say, 'C'mon, let's not look back. Let's just focus on what we can do to make this university a better place.' "
If all this weren't perilous enough for Penn State, there's also the matter of Paterno's precarious health.
Should he die and the ongoing investigations subsequently exonerate him, Penn State might never climb out from that public-relations abyss.
"Let's just start with a simple apology," Lubrano said. "That, I think, would be a very good beginning."
In any event, the message was delivered at Valley Forge:
Don't Tread on Joe.
Contact staff writer Frank Fitzpatrick at 215-854-5068, firstname.lastname@example.org, or @philafitz on Twitter. Read his blog, "Giving 'Em Fitz," at www.philly.com/fitz