Ash, I'm sorry for your loss but I don't think that you being out of town for a brief bit of time was a major cause. A lot of times, our snakes are sick and they don't show any outward visible signs. I read somewhere that a lot of people make the comment, "He just got suddenly sick" or "he wasn't like this yesterday". That's usually not the case. I believe there's an entire article about this in this month's Reptiles magazine. They say it a lot better that I can.
If you have had problems feeding him for the past 5 months and he kept regurgitating, then I would have thought that you would have made a vet visit quite some time ago. Dehydration also occurs over a period of time. He may have had internal parasites that caused him to regurg or possibly he never had enough time to replenish his gut flora...which resulted in the same and contributed to the dehydration. At either rate, probably between the dehydration and lack of eating, trying to feed him wasn't a good idea,
IMO. Without knowing the entire story, I'd suspect that the vet may have been wrong in recommending that. On the other hand, I'm new at this, so I could also be very wrong.
Hope this bad experience doesn't turn you away from herps. Learn from here, get another from a reputable breeder and you'll have years of happiness together.
[addsig]