On March 8, 2004, Moore was playing in a game versus the Vancouver Canucks. Late in the game he was punched from behind by Todd Bertuzzi while skating up-ice, knocking him unconscious immediately. The 245 lb (112 kg) Bertuzzi, purposefully or accidentally, then continued to propel his body on top of the unconscious Moore (205 lbs), pushing him towards the ice. Colorado Avalanche player Steve Konowalchuk dogpiled on top of him, then teammate Andrei Nikolishin jumped onto the back of Bertuzzi in an attempt to protect Moore. This action potentially worsened the situation, as Moore now had two players falling on top of him. Moore sustained a neck injury and concussion, and was taken off the ice on a stretcher.

The incident likely came about as a result of a February 16 game between the two teams in Denver, in which Moore inflicted a questionable hit on Vancouver Canucks captain Markus Näslund, causing him to miss the next three games with a concussion. Although Naslund was injured, both the referee on the ice and the league ruled that the hit was legal. That incident caused Canucks head coach Marc Crawford to publicly criticize the non-call by the referees on the incident. Other possible factors for Bertuzzi's actions include the rivalry between the two teams, the fact that the home Canucks were losing badly at that point in the game, and that Moore had refused to acknowledge repeated fight requests from Bertuzzi and Matt Cooke. Bertuzzi and Cooke were seeking retaliation for Moore's February hit on Näslund, but Moore was unwilling to throw his gloves down during the waning seconds of the game, having already fought Brad May and Cooke in an earlier contest between the two teams at the conclusion of the Naslund incident.

“ I think it's a marginal player going after a superstar with a headhunting hit. ” -Vancouver GM Brian Burke (Speaking on Moore's hit on Naslund) Moore had also come under criticism earlier in the week after cross checking Tampa Bay Lightning star Martin St. Louis from behind into the boards on March 1. This led to Lightning coach John Tortorella to call for increased protection for St. Louis in the St. Petersburg Times, and the NHL reviewed the hit.

On March 22, 2004, Moore was released from a Denver-area hospital. He was expected to wear a neck brace for 6 to 12 weeks and begin physical therapy after he recovers from his neck injury and concussion.

By December 2004, Moore was back to doing light workouts but had not resumed skating or playing hockey. Several news sources speculated that he would file a civil lawsuit against Bertuzzi, but in December 2004, he publicly stated that he would not do that unless doctors told him that he could never resume playing in the NHL. However, on February 17, 2005, one day after the 2004-05 NHL season was canceled, he filed a lawsuit against Bertuzzi, May, Brian Burke (the Canucks' general manager at the time of the incident), and the Canucks team. He chose to file the lawsuit then because of the state of Colorado's laws pertaining to the timing of lawsuits. The lawsuit was thrown out in October of 2005, as the Colorado judge felt that British Columbia was a better venue for the suit.

As of August 8th, 2005, Todd Bertuzzi was reinstated to play in the 2005-2006 NHL season. At the time, several news agencies reported that Steve Moore had commenced working out and skating in the Toronto area. In the decision ending Bertuzzi's suspension, the NHL commissioner Gary Bettman noted that Steve Moore had not been under regular medical care for some time.