The incident occurred early in the fifth hour when Bamber jinked right to try and pass another Hypercar, the #99 Proton Competition Porsche, as they sped up the Kemmel Straight.
However, the New Zealander had not cleared the #31 WRT BMW GT3, and the contact caused the #2 Cadillac Hypercar to spear into the wall on drivers’ right before almost rolling.
The BMW also sustained heavy damage in a crash which caused a red flag period.
Stewards determined Bamber was to blame, meaning three penalty points on his licence and a five-position grid penalty for his car at his next race, which is set to be next month’s 24 Hours of Le Mans.
They found that Bamber “hit car 99 and moved to the right, causing a collision with car 31.”
Cadillac Racing and Team WRT reported that both drivers, the latter’s being Sean Gelael, were okay.
Bamber said later, “Great that Caddy built a strong chassis, so it’s nice to walk away from that one.
“It’s a real shame for the result because I think we on to something real good today. We showed really good speed today.
“I think we had good strategy, good speed, so again we showed like in Qatar that if we have things go the right way that we can definitely challenge for podiums in this championship. It’s good to realise that.
“Imola was just a bump on the radar performance-wise. And now we look forward to Le Mans.”
Bamber is set to share the Car #2 at Le Mans with Alex Lynn, his regular WEC co-driver, and Alex Palou.
Palou won the Indianapolis Grand Prix on the same day while former IndyCar full-timer Callum Ilott shared victory outright in the 6 Hours of Spa-Francorchamps with William Stevens.
Ilott is in the frame to rejoin McLaren for this month’s Indianapolis 500, with Theo Pourchaire locked in as David Malukas’ replacement for the rest of the season thereafter.