Validation is NOT a work permit and should not be considered as one by the employers or employees.
As you can see the Santa Barbara Pilots can be validated as long as they meet the basic validation requirements. The maximum duration of validation is a year which after it can be renewed.
(3) The requirements stated in (1) and
(2) above shall not apply where aircraft
registered in a JAA Member State are leased
to an operator in a non-JAA State, provided
that the State of the operator has accepted
(a) Licences, ratings, authorisations,
or the period of lease the responsibility for
the technical and/or operational supervision
in accordance with JAR–OPS 1.165. The
licences of the flight crews of the non-JAA
State operator may be validated at the
discretion of the Authority of the JAA Member
State concerned, provided that the privileges
of the flight crew licence validation are
restricted for use during the lease period only
on nominated aircraft in specified operations
not involving a JAA operator, directly or
indirectly, through a wet lease or other
commercial arrangement.