One of the especially insufferable voices in me regards regular English past participles as games and automatically swaps them for vowel-changed forms mid-sentence while I read.
"PERMANENT UNDERCLASS[: has been] ESCUPT"
I mean think of it this way:
When we say "noun past-tense verb" there's an implied colon or equals sign which takes the place of the "has been" past participle. Ex: "Car: driven." or "Car=driven." and never "Car: drove" because what we really mean is "the car has been driven."
Now on the vowel change vs. -ed/-en endings--I prefer "swim, swam, swum" to "drive, drove, driven" but it doesnt work on its own here "escape, escope, escuped" feels wrong. So we get our "Watch him escape, he just escope, now he's escupt."