But he wasn't too stunned to make the shots, and the free throws were among Roy's 28 points in Portland's 107-105 victory against Indiana on Wednesday.
"Yeah, I was a little surprised because any time you make a call with one or two seconds on the clock there's going to be arguments," Roy said.
The Blazers, who trailed by as many as 14 points in the second half, have won 10 straight at the Rose Garden, where they are 25-5 overall.
The victory also snapped Portland's nine-game losing streak against Indiana. The Pacers had won four straight at the Rose Garden.
Marquis Daniels had 28 points for Indiana. Troy Murphy had 11 points and 13 rebounds for his ninth straight double-double.
A 14-0 run early in the fourth quarter gave the Blazers a narrow lead, which they held until T.J. Ford's jumper put the Pacers back up 99-97.
The teams wrestled until Roy's pull-up jumper put Portland ahead 103-101 with 1:22 to go. Roy added a pair of free throws with 40.5 seconds left.
But Daniels made two free throws of his own before a dramatic steal and dunk with 11 seconds left to tie it at 105.
Ford was called for tripping Roy on the other end, and Portland's All-Star guard put the Blazers ahead. After a timeout, former Blazers guard Jarrett Jack missed a 3-point attempt from out front at the buzzer.
Jack said the call was fair.
"I thought it was a tough call at first but we came back and looked at it and thought the ref had a better look at it than we did," he said. "We have no gripes or complaints."
The Pacers, coming off a 117-109 victory against Sacramento on Tuesday night, remained without All-Star forward Danny Granger, the team's top scorer, who is recovering from a torn tendon in his right foot.
The Blazers remained without Greg Oden, who has missed eight games because of a bone chip in his left knee. The Blazers said the injury will be reevaluated in about a week.
The 7-foot center was hurt in a collision during a game at Golden State before the All-Star break. The top pick in the 2007 draft sat out last season after microfracture surgery on his right knee and he missed six games early this season with a foot injury.
Indiana took a 35-24 lead in the first half after Daniels' dunk. Portland pulled within 38-37 on Travis Outlaw's layup off a well-timed pass from Rudy Fernandez.
The Blazers could not get closer and the Pacers led 59-52 at the half.
Indiana stretched the lead to 79-65, seemingly unaffected by having played the night before.
Portland narrowed it to 88-86 in the fourth quarter with Fernandez's 3-pointer from the corner. Steve Blake added another 3-pointer to give the Blazers an 89-88 lead.
Another Blake 3 made it 92-88, capping a 14-0 run.
The Blazers moved to within a half game of the Northwest Division-leading Nuggets, setting up a battle for first place in the division race when Portland visits Denver on Thursday night.
"It's going to be nice. I just wish we didn't have to get them on a back-to-back but we'll be ready," said Travis Outlaw, who had 21 points off the bench.
Indiana's last loss in the series was a 97-95 overtime defeat Dec. 3, 2003, at the Rose Garden. ... Before the game, the Blazers helped raise money to help pay for the care of Nathan Vredevelt, a 16-year-old with Down syndrome, who was struck by a car and critically injured after wandering away from Sunday night's game at the Rose Garden. The team said it would match donations up to $10,000. ... Boxer Roy Jones Jr. attended the game. Jones is promoting a fight this weekend at an Oregon casino. ... Pacers president Larry Bird also was at the game.