IP and Missed Base

[argodad]

NFHS.

One of our umpires had this happen last night:

Runners on 2B and 3B. Illegal pitch called by base ump. Pitch is not hit. Plate calls dead ball and awards runners one base. Runner from 3B misses home plate, is still in live ball territory, but is making no move to come back to touch the plate. Defensive coach requests time to ask the BU about the IP call. Passing the plate ump, he asks, "Did you see her miss the plate?"

1. Is this a dead ball appeal?
2. When a runner is advancing on a dead ball, when does she no longer have the right to return and touch the plate?