Q&A

Bought my 04 TB new. Religiously change oil, tire rotations, take better than average care of her. May 2009, 65,000 miles, water pump failed. While in the shop, my regular mechanic (whom I trusted wholeheartedly since I was recently widowed) suggested radiator & trans flush. I agreed. Fast forward Aug 2009, 67,000 miles, trans gets stuck in low gear. First thing I said to my mechanic was 'we just flushed the transmission. How could this happen? He outsourced to trans shop. Reg mech gives me 3 options, $1900 to replace parts, $2700 for new trans, $3800 for lifetime warranty on new trans. I took the lifetime warranty knowing I wouldn't be buying a new vehicle for a long time. Fast forward again to May 2010, transmission overheats in SC on my way from FL to MD. SC transmission shop finds that line from radiator to trans cooler was clamped off not allowing coolant to trans. Since I was laid off and don't drive as much, it was just a ticking time bomb. He says this caused the overheating. Repairs were made to 2nd trans which cost me another $500, plus a rental, hotel stays, etc. He also said the Lifetime warranty was not a lifetime warranty but a limited warranty and that the transmission was not replaced as new. (whole other issue) Between May 09 and May 2010, spent $7,000. I am hearing that if a trans has not been flushed before 50,000 miles, recommend not to flush.
Couple of questions:
1st - could the flushing have caused the 1 trans to fail?
2nd - how can a person tell if the trans was new? How would I have ever known?