Against Virginia Tech, McAdoo missed a dunk on UNC's first possession. The Tar Heels' next five possessions resulted in four missed shots and two turnovers.
The Hokies, on the other hand, scored on five of their first six possessions to build a 12-0 lead.
"We weren't ready to play," senior guard Dexter Strickland told reporters when asked about his team's poor start.
Freshman point guard Marcus Paige agreed with his veteran backcourt partner.
"I think it was just a lack of effort," Paige said following UNC's 72-60 overtime win. "We just weren't getting to the right spots. We didn't have a sense of urgency and that's been a theme a lot throughout this year, but we were able to correct that and that's huge for us."
North Carolina was able to overcome the sluggish start, but the process involved was slow and arduous. With Hairston sidelined with a concussion, UNC was limited offensively in attempting to deploy a strike to erase the 12-point deficit.
It would take the Tar Heels more than 30 minutes to take its first lead of the game.
When asked how many more slow starts his team could weather, Paige replied: "Not very many."
"Hopefully we're out of those," he continued. "We've just got to come out with a little bit more energy [and] effort. And when we see the other team make a basket, we have to come down and get a good shot instead of coming down and rushing, because that's how teams end up going on runs."
North Carolina's 12-0 deficit prompted Roy Williams to do the unthinkable – call a timeout.
"It just wasn't very good basketball," the 10th-year UNC head coach said. "I started just to stay there and leave it to see how many they could score in a row against us. I don't ever think you lose or win in the first two or three minutes of the game."
A significant part of the issue has been poor play by the starting lineup – Paige, McAdoo, Strickland, Reggie Bullock and Desmond Hubert. Over a span of five halves beginning in Raleigh, UNC's first five scored just seven points in 29 possessions.
That collection of players offered signs of reversing that trend, however, by scoring 10 points on seven possessions after halftime on Saturday.
Credit the Tar Heels with grinding out a critical victory at home as they continue to build their NCAA Tournament resume. If UNC continues to spot its opponents leads off the tip, however, its postseason hopes could eventually encounter a devastating blow.