Stewards however elected to take no further action.
Campbell had been searching for a way past Mostert for a number of laps when he showed the nose under brakes at The Chase, taking third position when he hit the Schnitzer BMW in the side and put it off the track.
The eventual race winner had started his final stint on brand new tyres while the remaining half-dozen crews still vying for victory chose to pinch track position instead of taking the time to switch to fresh rubber in the pits.
Earl Bamber Motorsport's #912 Porsche 911 GT3 R had been leading when Dennis Olsen pitted for the final time to hand over to Campbell, who had to fight his way back from fourth once the stops completed.
Speaking before the result of a post-race investigation, which saw no penalty levied against Car #912, Mostert believed that allowing the incident to go unpunished would be a fair outcome.
“We're racing wheel-to-wheel, I blocked as much as I can, and I kind of got hit in the rear and it kind of pushed me wide,” recounted Schnitzer Motorsport's hired gun.
“But he was on a much better tyre so I was being pretty optimistic.
“At the end of the day, congratulations to him, he's another Aussie, it was good to see him get the race win.
“I'm a pretty defensive driver so whatever the outcome is, the outcome is, but it would probably be rude to take it off him.
“He had a much faster car and he was driving the wheels off it so for me it was good to have a battle to the death but I really had nothing left for him.
“To be honest, I think he definitely deserved the win.”
Mostert went on to take the chequered flag in fifth position, which he deemed a commendable enough result for himself and co-drivers Augusto Farfus and Martin Tomczyk after they started 15th.
While BMW Team Schnitzer displayed some of the strongest pace at Mount Panorama 12 months ago, highlighted by the Supercars driver qualifying on pole position before he set off a multi-car accident at Forrest's Elbow that cost them a finish on Sunday.
Mostert maintains that the whole team made a step up even if it lost the lap speed advantage which it possessed in its first attempt at the Bathurst 12 Hour.
“I think this year we definitely put our better foot forward than last year,” he declared.
“Last year it was a bit (of a case of being) thrown in the deep end, I think.
“This race is pretty unique, the way it unfolds, and they came back much more prepared this year, so no doubt if they come back again next year they'll take it another step.
“They're a really good team for actually learning from things and chipping away, and we did the best job we can.
“For the drivers, we didn't get one pit lane penalty, we didn't get any incidents, we didn't get any damage with the car, so I think Augusto and Martin can really give a pat on their back because it's tough out there with the traffic.
“The car balance was even better than last year, we just lacked some pace compared to some other cars, but we did good, we stuck to our strategy, and I think, to be honest, to be within podium contention from starting 15th, I think it was a really, really solid effort from Augusto, Martin, and Schnitzer and BMW.
“I think we did the best job we could, and at least we had a fight for the podium but it wasn't meant to be today.”
With the heat a major battle for a number of rivers, Mostert revealed that the trio even had to persevere without any form of cooling when the M6's air conditioning failed.
“Our air conditioner failed after the first stint, and no airflow whatsoever,” he explained.
“It's not like a Supercar where we have vents going in there; they seal these GT3 cars up so obviously they think there's a big gain in it and it was really tough.
“Mentally it was tough; you see Gizzy (Shane van Gisbergen), he looked really buggered as well, and it really showed how hot it was out there today, so this was probably the most rooted I've ever felt coming out of a race car.
“We don't have a coolsuit, we purely just run off the air con, so when the air con fails, that's it.
“Lovely double stints at the end,” he mused.