Bob, well, it finally happened to me. I was driving a long 3 hours trip from Austin to Houston on my 95 LS and when I got off ramp, the engine just quit like you described. I never experienced this problem before, maybe because, I just guess here, that I had always shifted to the 3rd gear to slow down the car and therefore accidentally ramping up the rpm - avoiding the ECU problem?!
This situation is quite dangerous that I think Lexus should do a recall on it. I will attempt to talk to Lexus dealership this week to see if they can fix it free for me. If not, I may have to send a letter to Lexus regional or national customer care general manager. Can you imagine how many senior drivers would handle this situation without going panic and causing accidents?
Again, you are doing a great service for all of us here! Thanks mucho!