REALLY? BROKEN FLYWHEEL?

This is a non-mopar but it's mainly a rant anyway: I have a 2008 Ford Ranger with a 4 cyl. w/Automatic 5 OD. 248,000 miles. Transmission went out, lost 3 forward gears and reverse.
I don't have the time to work on it so I took it to the most well known tranny shop in the country. Paid out the *** for rebuilt trans and converter. 30 days it's leaking and slipping, they fix the leak but still missed a gear now and then, so brought it back and they replaced the trans and converter under warranty. Two months later about 5,000 miles, (I drive 100 miles a day) I hear a noise that sounds like an exhaust leak followed by a complete loss of forward motion while at speed. Engine still running but trans just spinning. Tow in to trans shop and the diagnosis is a broken flywheel from "normal wear and tear". I knew the flywheel or somthing had broken, but I feel it has to do with the rebuilt trans or the installation. What do you guys think? Thanks in advance for your input