PORTLAND — The jury in the manslaughter trial of Ernest Weidul this morning learned the central question in the case: Did Roger Downs Jr. die from a brutal beating by Weidul or from an undiagnosed and untreated case of pneumonia?

Weidul, 52, is charged in the death of Downs. The two men – strangers before they met on May 5, 2010 – got into a fight after drinking coffee brandy together in Downs’ Forest Avenue apartment.

Downs woke the next day with injuries and called for an ambulance. He died on May 7 at Mercy Hospital.

In his opening statement, Deputy Attorney General William Stokes said Weidul told authorities Downs was being disrespectful by flicking him in the face, among other things. The prosecutor noted that Weidul told a police detective he had hit Downs “too many times” – perhaps 30 times.

Downs died at the hospital after experiencing severe respiratory distress. The doctor tried to insert a breathing tube but Downs’ larynx was too swollen. The doctor performed a tracheotomy, but Downs died.

Stokes told the jury that Weidul’s vicious bludgeoning of Downs caused the hemorrhaging to his neck and chest.

Amy Fairfield, one of Weidul’s lawyers, said the fight was a matter of self-defense and that Weidul had the right to defend himself against a drunk and much larger man that was going after him.

She said it took the state medical examiner six months to conclude that Downs died from streptococcus pneumonia. As an alcoholic and heavy smoker, Downs was more susceptible to pneumonia. She said the hospital did not administer any antibiotics for the disease.

Meanwhile, there was a rush to judgment about the case, Fairfield said. She said Portland police immediately called the case a homicide and missed the actual cause of death.