In the first half of the Roosters' 31-24 win on Saturday, Walker hit David Klemmer in a cannonball tackle, entering the fray late and targeting the prop's legs to bring him to the turf.
The dangerous first-half shot at Kogarah Oval put a damper on the marquee halfback's first game for 314 days following knee and thumb injuries.
Walker had some clunky moments, including a first-half forward pass and six missed tackles, but gave the Roosters the lead with a field goal before the break and then laid on a crucial try after it.
"It was a mixed bag but after a year out, an ACL, it's good to have him back," Roosters coach Trent Robinson said.
Sporting headgear on return from his latest concussion, Victor Radley flew in for the game-sealing try in the final three minutes by grabbing a high inside ball from James Tedesco.
Walker will face suspension if he receives anything more severe than a grade-one charge but downplayed the tackle after fulltime.
"It didn't feel bad at all, I've made that tackle a million times and it's never been a penalty," he said.
"This time, obviously the fact that I hit him on his booty, and obviously he went down, the people coming over the top of me didn't make it look pretty.
"But I'm not going intent to try and chop out his knees or anything like that. I personally think (the sin-binning) is a bit ridiculous but I understand the safety of the player.
"There's not a world where I'm trying to hurt David Klemmer in a tackle like that."
Robinson likened the tackle to schoolyard shenanigans, hinting it was not as serious as the shot from Karl Lawton that injured Roosters forward Siua Wong in round 16 and resulted in a two-game ban.
"It was like the old school-yard, kneel-down behind them and push them over, type thing. It's something we don't want to see, but there's no force in that," Robinson said.
"We've had guys out for six weeks with MCLs with no penalties, and all of a sudden we get a sin bin for that. I was surprised."
The two sides scored a staggering five tries between them in a frantic first 17 minutes.
Walker's edge put Daniel Tupou over for two tries as the veteran feasted on Tyrell Sloan, but Saints' Sione Finau gave his own opposite man, rugby convert Mark Nawaqanitawase, the same treatment.
Walker put the Roosters up by a point with a field goal from 12 metres out in the final minute of the first half, and then threw a beautiful flat ball to Billy Smith that gave the visitors their fourth try.
After some good chances, including a Jacob Liddle knock-on over the line, the Dragons finally had second-half points through a lovely Kyle Flanagan short pass to Jaydn Su'A on the right.
But as in last week's loss to Canberra, they had to settle for gallant defeat and are set to finish the weekend four competition points out of the top eight.
Dragons coach Shane Flanagan was left to rue conceding the two Tupou tries in the opening 10 minutes of the "frustrating" loss.
"In the end, that's the game," he said.
"After that, we got in a bit of an arm-wrestle, played some good football but you can't gift any team, let alone the Roosters, 12 points at the start of the game."
