I was on UA7 on 1 May. We diverted to SLC for a medical emergency. Sat there 6 plus hours. Had dumped fuel to land, refueled to go to NRT, crew timed out, took out fuel and flew to SFO. So yes there was no plane arriving into NRT on 2 May to become UA 6 back to IAH. I ended up on UA 875 to HND the next day which worked out better. Got to go into the new Polaris lounge.