That's explicitly why I called out crimes committed as part of the escape and evasion as a potential example of "subsequent crimes that don't qualify for the death penalty". There are too many valid mitigating circumstances to just blanket say "he's a convicted murder, and he escaped, now we get to kill him".
I'm not sure I'd go so far as to say that escape shouldn't be treated as a crime (one way to view crime is an explicit rejection of the idea that a government can or should dictate our actions, so in that light, trying to get out of a legal punishment is itself a rejection of that government's right to issue punishments). But certainly, if the only additional crime is the escape itself, then the death penalty is entirely unwarranted.
I'm not sure I'd go so far as to say that escape shouldn't be treated as a crime (one way to view crime is an explicit rejection of the idea that a government can or should dictate our actions, so in that light, trying to get out of a legal punishment is itself a rejection of that government's right to issue punishments). But certainly, if the only additional crime is the escape itself, then the death penalty is entirely unwarranted.