On a frantic afternoon at Allianz Stadium, Luke Keary saved the Roosters with a late field goal after they let a 16-point lead slip in the second half.
Keary and Joey Manu had the Roosters' attack flowing freely in the halves, after a week where all the attention was on Sam Walker's relegation to reserve grade.
Manu showed what he can do with more freedom and more ball when he charged across for a four-pointer in the second half, while Keary scored one when he dummied and went himself.
But the story of the match remained Radley's third sin bin in as many weeks after a tackle on Michael Molo.
Radley immediately argued it was a head clash, and later told Fox Sports it was a "s**t decision", while Tedesco remonstrated with referee Adam Gee on field.
"I just said if it was anyone else but Victor, it would have been OK," Tedesco said.
"But if there is any contact around the head ... Victor gets harshly treated.
"I haven't seen all angles, but Rads was adamant it was head-on-head, that's all I saw."
The sin-bin was the ninth of Radley's career - a record in the NRL-era.
"I think Victor gets treated differently, just because of the aggression he plays with," Roosters head coach Trent Robinson said.
"It doesn't mean that's the truth. That's my opinion and Ted's opinion. That doesn't mean it is real, we might be biased.
"We feel like if it's a 50-50 in a physical contact then Rads has been on the other end of it. That's an opinion, I don't know if there is fact about it."
Radley's sin-binning came as Dragons fullback Tyrell Sloan inspired St George Illawarra to go from 26-12 down in the 50th minute to level eight minutes later.
Sloan first stepped past Joseph Aukuso-Suaalii and Keary and put on a flick pass for winger Tautau Moga to cross.
From the next set he put Moses Suli into a hole and then loomed up on the inside to step past Jaxson Paulo and go in under the posts.
Moments later Sloan handed off to Suli, who fended off two Roosters on the spot and helped Moga score his third, with the winger dislocating his shoulder in the process.
Sloan then missed a chance to give the Dragons the lead when he was unable to collect a Talatau Amone grubberkick as the Dragons went scoreless with Radley off.
Instead, it was the experience of Keary and Manu which brought the winning play, when the former jumped out of dummy-half and passed back to his halfback for the field goal.
The result left the Dragons 13th on the ladder with two wins and five losses, as further pressure is heaped on off-contract coach Anthony Griffin.
"It's a cruel game at the moment for us," Griffin said.
"We're struggling to close games out when we get in the position to.
"We just have to stare that in the face and get better. When we do, we will win a lot of games."
In a blow to NSW selectors with Josh Addo-Carr already injured, Roosters winger Daniel Tupou suffered a serious-looking hamstring problem five weeks out from State of Origin I.
