It was thought to be just a blip. It ended up being a sign of things to come, one of the big reasons Georgia fell in its next four games.
The young Bulldog secondary has proven to be a weakness in Grantham's first year. Georgia ranks last in the SEC in pass defense efficiency, a stat that measures an opponents' completion percentage, passing yards and touchdowns.
The Bulldogs are eighth in opponents' passing yards per game, and seventh in third-down defense.
But it's the glaring conversions that stand out.
"If you look at all the games those explosive plays is what's killing us on defense," Grantham said.
Last week, Colorado's second touchdown was set up by a 35-yard pass down to the 1.
When Georgia took a 24-14 lead in Boulder, the Buffaloes got a 65-yard rush – an option run to the left - that set up a touchdown. Late in the game, Colorado converted a third-and-13 from its own 28, when Rodney Stewart was wide open in the flat.
At Mississippi State, there was a 33-yard touchdown pass to make it 17-6.
Grantham didn't want to pin all the blame on the secondary, saying big plays result from breakdown in all areas, even the front.
"I think it's a combination of youth, newness to the system," Grantham said. "I think it's a combination of that. I wouldn't say it's just one thing, one person."
Cornerback Brandon Boykin said the answer was simple.
"Everybody being focused on what they gotta do each and every play," Boykin said. "I know that you're out there 50, 60 snaps a game, you kind of get tired and mentally tired. And the one time you do that's when you give up a big play."
Safety Bacarri Rambo has been on the receiving end of some of Grantham's ire. As a unit, Rambo thinks players have critical mental errors that cause the breakdowns.
"We've got a mental weakness. Everybody's got to get their mind right," Rambo said. "Start focusing on your gameplan and do your job. That's what coach Grantham has been emphasizing."
Perhaps the secondary's trouble should have been anticipated. It is a very young group, with Rambo the most experienced safety being just a sophomore. Cornerback Vance Cuff is a senior, but he's an excepetion.
"Unfortunately you don't have time for growing pains," said secondary coach Scott Lakatos, who is also in first year at Georgia. "That's the hard part. The other team doesn't care how young your secondary is, they're gonna run their offense, and you've gotta stop them. That's certainly not an excuse for the way we're playing, we've just gotta get better."
Georgia has been rotating three players at safety: Rambo, Jakar Hamilton and Shawn Williams. Don't look for a change in that setup: Alec Ogletree has potential but is still a freshman, and junior Nick Williams has been playing a hybrid linebacker-safety spot when the team switches to a 4-2-5.
"I don't know who else we could stick in there at this point in time," Lakatos said. "They all have their plusses and minuses. The key is to make sure that the minuses don't get exposed."
The cornerback situation is seeing some changes, but mainly due to Branden Smith's concussion. Boykin and Vance Cuff are the top two, while Sanders Commings, Jordan Love and freshman Derek Owens are seeing more work.
But the coaches say the effort is there, at least off the field. Boykin was in the film room on Sunday, while some teammates were catching up on sleep after the plane ride back from Colorado.
Rambo has started tackling the way they want to tackle, and come in to watch extra film.
"There's a guy that I kind of got on early in the year," Grantham said. "But I've seen him progress to do things more the way we want them to be done."