I've noticed that in the monster block of Monster Vault creatures with a special grab ability/attack the escape DC for their grab is explicitly stated (example: Mind Flayer Thrall Master).
Tentacles - At-Will
Requirement: The mind flayer must not have a creature grabbed.
Attack: Melee 1 (one creature); +17 vs. Reflex. This attack automatically hits a dazed or stunned target.
Hit: 3d6 + 5 damage, and the mind flayer grabs the target (escape DC 21) if it does not have a creature grabbed.
But, as far that I know, escaping a grab is either a [grabbed's] Athletics vs. [grabber's] Fortitude check or an Acrobatics vs. Reflex check.
You attempt to escape from an enemy who has grabbed you (see “Grab”). Other immobilizing effects might let you make escape attempts.
ESCAPE: MOVE ACTION
Acrobatics or Athletics: Make an Acrobatics check vs. Reflex or an Athletics check vs. Fortitude against the creature or effect that immobilized you.
Check: Resolve your check.
Success: You end the grab and can shift as part of this move action.
Failure: You’re still grabbed.
In the example above, the escape DC 21 doesn't match neither the Fortitude (23) nor the Reflex (27) defense of the monster.
Is this intended as an alternate (and easier) DC for both the Athletics and Acrobatics checks to escape? (Because, of course, specific beats general?)