Having generally described apathy as a lack of concern or interest, I would say that it is a matter of attitude of a person. To say whether it is evil or not depends on why he was not concerned in the first place.
Some people are not even bothered about their own appearance, going about disheveled, clothes torn and tattered and dirty, unwashed - all these due to not taking an interest in their own hygiene. I do not call this evil as I equate evil with wicked.
Like BU pointed out, if it was a crime that had been witnessed and no one did anything to help, then it was indeed evil.