(or did the gear retract itself after you put the landing checklist away? )
Well, I've had gear go from "3 greens" to "2 greens and 1 red" after completion of the landing checks.
And I've also seen flaps indicate running during the take off role.
The former was probably an indication error, the later certainly was, but we went around for the first and stopped for the second. So if its all the same to you, I'll keep including flight phase critical stuff in my scan.
pb