Texas Impreza Club checking in... this is an atrocity!
This kind of crap just is just plain bad news. I work for a dealership, and yes, the tech's will do everything in their power to PROPERLY diagnose a problem (most of which can be found by plugging into the OBD-II) Our techs will go out and diagnose road problmes at NORMAL operating speeds/situations. See the emphasis on "normal" (not 140mph)
This guy is a moron, plain and simple.
Sorry to hear about this.
-Kevin