This is possible of course. However this is also assuming that the police did not do an investigation to determine things like how far the gun was when the shot was fired, the angle of entry, gun shot residue on his hands or her hands, and blood spatter evidence. The story sounds suspicious.
I see nothing suspicious in the assumption that people in general believe women over men in custody & abuse cases. IN GENERAL that is. Men are often pigs, but women are often pigs too.