I'm going to have to say that for the most part you should not tumble loaded rounds. I have seen folks post that they did it plenty of times, but the little voice in my head still says not to do so.
I highly doubt that you ruined the lube on your bullets, but I can suggest that you possibly broke down some of the powder or at least possibly some of the coating on it, which allowed you to get a faster burn rate than you had before, resulting in more velocity and leading. This is simply a WAG on my part, but this has been why I have always heard not to tumble loaded rounds.
If you have an Alox based lube and want to pretty up the noses, simply take a rag with a touch of rubbing alcohol or even better denatured alcohol, and it will wipe right off. It will easily cut the Alox and evaporate plenty quick enough so as not to seep into the case.
When you clean your barrel take a dab of Alox smeared into a patch and run it through your bore prior to shooting. This will pre-lube the bore for the first round. That way, if by chance, cleaning the lube off the noses is an issue, you have corrected it ahead of time.
You didn't mention if your leading started at the chamber end or the muzzle end of your barrel. If from the chamber end out, then I would bet on a velocity change, if nearer the muzzle I would go with the lube.
Mike / TX