When Pascal Siakam launched a 3-pointer with three seconds left Fridayin Toronto, DeMar DeRozan had seen enough.

The Raptors led by 13. The shot clock had shut off and the Bulls had sagged back to allow the final seconds to play out. But coach Darko Rajaković and the Raptors bench were still shouting: “Score, score, score.”

Siakam followed orders, launching a 3-pointer with three seconds left. DeRozan erupted in immediate indignation, storming toward the Raptors bench to shout down coaches and players alike. He continued to stare down several former teammates after the referee ejected him with his second technical, hugging Raptors owner Masai Ujiri in the tunnel before ripping his jersey off in frustration on the way to the locker room.

It all came from a misunderstanding. The Raptors — who seemingly forgot they already were eliminated from In-Season Tournament advancement — thought they still needed to pad their point differential. But DeRozan didn’t care for the reasoning.

“I don’t care about no in-season tournament points,” DeRozan said. “None of that. It’s just respect for the game. If roles were flip-flopped and I had the ball, I’d hold it. Simple as that.”

DeRozan’s ejection with 1.4 seconds remaining was only the final crack in another frustrating night for the Bulls, who are 5-12 after losing to the Raptors 121-108.

Here are four more takeaways from the loss, the Bulls’ sixth in seven games.

1. Another slow start continues a worrying trend.

The Bulls already were the worst first-quarter team in the league. That trend didn’t improve as the Bulls fell behind by 14 in the opening quarter, scoring only 22 points while shooting 8-for-18.

That quarter essentially defined the game. The Bulls tied the second quarter, lost the third by two points, then won the fourth by three. But falling behind by double digits in the opening 12 minutes created a challenge the Bulls could not overcome.

Coach Billy Donovan felt the cause of the slow start was different from past games — rather than poor shooting, it was a lack of defensive rigor that allowed the Raptors to batter the Bulls around the rim and rack up points through high-percentage shots.

2. Zach LaVine fuels offense in return from injury.

LaVine returned to the starting lineup after missing Wednesday’s game against the Oklahoma City Thunder with a right midfoot sprain. LaVine was listed as questionable and his availability remained a game-time decision, but he appeared to be more comfortable on the court Friday after recording two low-scoring games against the Miami Heat while playing through the injury.

LaVine torched the Raptors at the rim and behind the arc, scoring 36 points off 16-for-23 shooting. He went 4-for-8 from behind the arc but was unable to draw a single free throw. This is LaVine’s third game of the season with 30 points or more.

3. Alex Caruso exits early in third quarter with a foot injury.

A familiar concern spiked for the Bulls again when Caruso was forced to exit the game midway through the third quarter after his left foot was stepped on. The accidental contact aggravated pain in the foot. He previously missed two games with a sprained toe in the same foot.

Caruso was in enough pain to alert Donovan, who chose to sit the starting guard for the remainder of the game after he was subbed out with 7:35 left in the third quarter.

Although he considered putting Caruso back into the game when the deficit was cut down to single digits, Donovan chose to be conservative with his most injury-prone player.

“I don’t know if he could have gone back in the game,” Donovan said. “It was definitely more of my decision. I know he was hurting enough.”

Caruso underwent treatment after the game. He voiced optimism that he would be available for Sunday’s game against the Brooklyn Nets, but the team has not set a recovery timeline for the injury.

4. Bulls eliminated from In-Season Tournament advancement

The loss Friday officially dashed any last-ditch hopes for the Bulls to advance to the quarterfinals of the In-Season Tournament. After dropping two games, they already had fallen out of contention to win Eastern Conference Group C. With their third loss, it became impossible to win the East wild-card bid.

The Bulls will play their final group-stage game against the Boston Celtics on Tuesday. The league will conclude group play that day, after which the schedule for the quarterfinal and consolation games will be announced.

Since they will not be scheduled for quarterfinals games, the Bulls will play two East opponents between Dec. 4 and Dec. 9 — one on the road and one at home.

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