A friend of mine did this in his transmission a few years ago and had to pay the stealership $1200 to pull the engine and fish it out. Personally, I would have just forgotten about it -- a cheap, plastic tube is going to get chewed up pretty quickly in the transmission -- I'd have run it for a few minutes, flushed with new oil and repeated a couple of times.
I think I'd be more worried if it were in my oil pan -- but, still -- how much damage is a plastic tube really going to cause to a bunch of hardened steel parts??
Former owner of a 1987 Supra Saltare. Current owner of a Malibu 23LSV.