MIAMI -- The Chicago Bulls' momentum turned upside down all night in their 115-78 loss to the Miami Heat in Game 2 on Wednesday thanks to the sound of the referees' whistles.

While many will focus on all the whistles the Bulls endured toward the beginning of the fourth quarter when official Scott Foster tossed Joakim Noah and Taj Gibson, one of the biggest came midway through the first quarter when Jimmy Butler was called for his first foul while trying to check LeBron James.

After having so much success against James in Game 1, especially through the first three quarters, Butler admitted that his game plan altered after hearing the first whistle directed toward him.

"I feel like after one foul I couldn't be as aggressive," Butler said. "I couldn't be the aggressor, and he took advantage of that definitely. He was definitely coming at me. But that's a challenge I got to take upon myself. My teammates are still going to be there, they're still going to be in [there to] help me, but I feel like it changes a lot. When you get a first one you start to back up a little bit and that's just like the green light for him."

It was a green light that didn't change all night. After being passive at times on the offensive end in Game 1 while looking to set up the rest of his teammates, James made it a point to find his offense early. Butler saw the difference in the Heat's play.

"That fire," Butler said. "They wanted to come out and be the more aggressive team. I feel like they got to where they wanted to on the floor, scored in the paint well; which is our fault because we're always talking about not giving up layups and that's all we gave up tonight."

That led to the frustration that boiled over for the Bulls late. The Bulls have gotten blown out during the Tom Thibodeau era but rarely have they lost composure the way they did Wednesday against the Heat.

"We got sidetracked," Thibodeau said. "We showed a lot of frustration to carry over to the next play. You have to have poise under pressure. You come in here, you're not going to get calls. That is the way it is. That's reality. You can't get wrapped up in that stuff. You have to stay focused on the task at hand. We have to get the job done."

Butler, who only scored nine points and had three rebounds after scoring 21 points and 14 rebounds in Monday's game, did not believe he or his teammates did the job they had to do.

"I feel like once frustration set it in everything went downhill," he said. "Our offense, our defense, us talking to the refs. We're not supposed to let the refs dictate how we play basketball. We're supposed to have the same style of game but I feel like that's what happened tonight. Once the refs started calling this call and that call, techs here, techs there, it went downhill."

After playing 48 straight minutes in the last three games, Butler did not take any solace in the fact he only played 31 in this one.

"I didn't like it," Butler said of sitting on the bench. "Not because I was playing 48 minutes; I feel like I let my team down. I didn't get any stops. I take it on myself to tell you the truth, to be the one to guard (James)."