Well, without having a personal look at the patient, I'd say probably. :( I'm sorry, as I can totally sympathize with you about this. I lost 2 bamboos when I tried planting them while we were building our house on the weekends. You could try to keep watering it, and maybe the rhizome is still alive and will sprout back next year, but I'd say it's probably RIP for your 'boo. How long was it in the ground before you went on your trip? If it wasn't long, then I'd say definitely dead. Sorry to hear about your 'boo. :( Mine almost died this year and I planted it early in the season. I kept watering it with old tea water and it sprung back. Maybe water it with some black tea water, it might help. Can't hurt, anyway.

I've had some come back from complete destruction in the past. Make sure you aren't watering too much. Chances are the root ball is already soaked and might be overwatering it. If so, it will definately die. Grab a $5 moisture meter from home depot/lowes. Never water until it is just about dry. Put it somewhere warm.

I had a sumatra with all brown (i.e. dead) culms for two years that sent up a shoot this spring. Didn't water it ever...only got rainfall (which ain't much in San Diego).