I feel that more often than not, the end result is a loss. It always feels bad.
I had recently asked the question, could those that stick it out receive a less LP loss for any team that has a person that qualifies as a leaver buster?
I know this could be abused as is. So, I would say that it only applies to teams that had the afk player over 10 minutes long. 10 minutes is certainly long enough to where it isn't clear if you will win or lose as a 5 man team. I wouldn't encourage a person to return after being out for 10 minutes since that puts the player too far behind in both gold and experience. However, I think it's fine if they return within 10 minutes to still see a comeback happen.
We are just looking at what would apply to the majority of the cases where this is true, not int-ers. I'm more interested in taking care of the players that are genuinely playing the game to climb in rank, rather than the punishment towards the afk-er.