So your point hinges on the various ways we can interpret the meaning of the word "escape."
As the Devil's advocate, I argue that a slave can "escape" just by being in a "free state" and claiming the right under those state laws.
Given that article IV is clear that it strikes down any state laws that interfere with what the home state laws require, I don't think your argument will hold much water if it was litigated in a court of the period. (Except in Massachusetts where they were kooky liberals even back then.)
As a matter of fact, the Dred Scott decision pretty much makes this exact point.
Your overly-clever lawyering here cannot erase the fact that nobody at the time understood it that way.
Indeed, if anybody in the world could successfully challenge Pennsylvania's right to abolish slavery in, say 1790, it would be President Washington, who knew exactly what the Constitution's words were intended to mean.
And Washington did not attempt to impose your too-clever interpretation of the Constitution's plain words.
Instead he obeyed Pennsylvania's abolition laws.