Maybe.
The karma answer is still theoretical. There is a truth for why this happened. But I don't think punishment/classroom lesson for past actions is the reason. There is something else at work here. And I will eventually get to the bottom of it, if it takes an eternity.
The karma answer could satisfy in a logical manner your doubts. As other answers maybe could be as well. I found that the karma answer is far more powerful than other theoretical models to explain with sheer logic and degree of probability the events unfolding in this realm.
Of course, there might be other logical answers, in your case it might have been a more or less random encounter with a victim, a good, naive man and a predator, a callous, evil materialistic man who does not mind inflicting pain on others . This answer may be logical since in this earthly plane good and evil souls coexist.