The Broncos moved to the top of the ladder with Saturday's thumping win at Belmore but Cobbo was placed on report and sin-binned in the 38th minute.
Referee Ziggy Przeklasa-Adamski penalised the Queensland State of Origin winger for leading with the forearm in a tackle by new Dogs playmaker Toby Sexton.
The Canterbury halfback did not return in the second half due to a grade-two concussion and Walters understood why Cobbo was penalised.
"He did get him in the chops, it's probably a fair reflection on that," Walters said.
Brisbane, who were without Payne Haas, Patrick Carrigan, Tom Flegler and Reece Walsh, have proven they can withstand absences from their first-choice 17 throughout this year.
It's that form which has propelled them to the top of the table, although second-placed Penrith play the Dolphins on Sunday and will fancy their chances of reclaiming first spot.
It was around this time last year that Brisbane self-imploded and missed the top eight but Walters says the 2023 incarnation of the Broncos is made of tougher stuff.
"I thought when the game was in the balance we got into a good groove in the second half and came away with a really important win for us given the time of the year," Walters said.
"We've got great depth in our squad this year and that was on show today."
Brisbane wrecked Josh Reynolds' farewell party at a sun-kissed Belmore with their own Reynolds - halfback and captain Adam - setting up three tries on their way to victory.
They had to contend with a spirited Canterbury side for much of the first half with a double from Jake Averillo and a crash-over from Jacob Preston keeping them in touching distance as they went in 22-18 down at halftime.
Brisbane's first-half tries came courtesy of Reynolds, Kurt Capewell, Billy Walters and Deine Mariner.
But the loss of Sexton to concussion proved critical for Canterbury.
Prop Xavier Willison scored while Cobbo was in the bin, with Ezra Mam and Herbie Farnworth further bolstering Brisbane's advantage for an eighth away win of the season.
"We lost Toby and Braidon Burns and that's not ideal having guys out of position," said Bulldogs coach Cameron Ciraldo.
"That's one part of the story but the other part is we let in 22 points in the first half.
"If we had defended well in the first half and that happens in the second half, you can understand things but to let in 22 points in the first half (was disappointing).
