Sudden aut0 Tranny failure..94 G20..questions

Hi, G20 owners..nice to find a place to discuss these cars. Daughter owns a 94 G20, 96K mileage, 4-spd Electronic auto tranny with 2 drive modes.
Son borrowed car last week, possibly in a bit of aggressive driving, he damaged tranny. He says he was going from 2 to 3rd, attempting to get over into another lane, at high rpm, when he lost 3rd gear ..totally. I'm not sure if he was manually shifting , or not. The car has run flawlessly, with no indication whatsoever, of a tranny problem, up until this happenned. Is it possible that the complete loss of 3rd gear could be electronic in nature(as in, over-reving shut down ? )..or, perhaps hydraulic, ie..clogged filter, valve body, ? Or does this sound like a total tranny crap-out? It doesnt slip, it simply won't go into 3rd gear, it goes from second...to absolute free spool mode. Any similar experiences, info, would be greatly appreciated.

Hello and welcome to the forums. I personally am not an expert in automatics, but apparently the Auto transmission in the G20 has a life span of 100k miles. Many members have had a failure of some sort around 100k, and have had to get a rebuild. My car is a 1994 with 98,360 something miles, and I haven't had any problems yet but my fingers are crossed. Hopefully someone else on the board can give you a little more help. I'll be checking my FSM..

Emily