After a pre-screening of the upcoming film “Deepwater Horizon” in Davis Square, Harvard faculty and other law experts offered insight into the the 2010 oil spill of the same namesake in the Gulf of Mexico and the extensive legal aftermath.

The film was screened in Somerville Theater on Wednesday for those with a Harvard ID and a guest. Panelists included Law School professor Richard J. Lazarus, who chaired President Barack Obama’s Commission on the Deepwater Horizon Gulf Oil Spill.

Originating in an explosion on the Deepwater Horizon oil rig operated by the energy company BP, the spill was the worst maritime oil spill in the history of the petroleum industry and sparked a massive response to contain the ecological damage, including a six-month moratorium on deepwater oil drilling in the Gulf.

Panelists described outdated U.S. oil regulations that enabled the spill, their experience investigating the disaster, and reforms they believe Congress and gas companies should implement in the spill’s aftermath.

“This was an unbelievable disaster that shouldn’t have happened,” Lazarus said of the spill. “What happened is that [BP] got complacent. They hadn’t had a disaster in a long time.”

Although panelists offered critiques of oil companies’ policies, the commission itself did not condemn deepwater oil drilling as a whole.

“Yes, [deep water drilling] is risky, but risks can be managed,” Lazarus said. “They’re being managed every day.”

The panel did agree, however, that legislators have not enacted sufficient reforms in the aftermath of the BP incident.

“Congress has done nothing,” Lazarus said, when speaking about reforms to mitigate the possibility of another spill in the future.

The panel also said the movie, which stars Mark Wahlberg, Kate Hudson, and Kurt Russell, depicted the events leading up to and during the oil spill realistically.

“I think it was a very accurate film,” Lazarus said. “The sense [that the movie provided] was exactly what it was like.”

Furthermore, according to Lazarus, BP was not the only oil company whose policies increased risks for a spill.

“Practices on the Deepwater Horizon were absolutely, 100% normal,” he said. “It happened to BP, but it could have happened to any of them.“

Lazarus also said the economic losses in the spill’s aftermath would have been more devastating for a smaller oil company.

“It was very fortunate that this was a company that had the resources to actually combat the disaster,” he said. “A small business would have simply declared bankruptcy and left it up to others to fix the problem.”

According to Lazarus, the spill also alerted the oil industry to the potential perils of unenforced regulations.

“I think [the oil spill] was a real signal to companies that the risks are real,” he said. “The accident cost BP $55 billion dollars.”

The panel also discussed changes in the private sector following the disaster. According to panelists, oil companies have developed new technologies and increased their focus on mitigation procedures after an accident.

Several members of the audience said the event alerted them to the risks of outdated rules.

“I think that the legal lesson is that there is a huge risk here and if you’re not putting the proper regulations in place, if you’re not monitoring what’s happening and what procedures people are using, you’re not managing that risk and you’re putting them in danger,” Gina M. Angiolillo, a Law School student, said.

The pre-screening was sponsored by Lionsgate Entertainment. Both the Commission’s report and the film were dedicated to the 11 men who lost their lives on the Deepwater Horizon rig.