Upvote:-1
Handlers are legally agents of the airline, so the airlines still bear the responsibility for their actions, as they would for any contractor/employee.
EU261 only mentions the air carrier and has no notion of 3rd parties involved.
For the purposes of this Regulation:
(a) "air carrier" means an air transport undertaking with a valid operating licence;
(b) "operating air carrier" means an air carrier that performs or intends to perform a flight under a contract with a passenger or on behalf of another person, legal or natural, having a contract with that passenger;
(c) "Community carrier" means an air carrier with a valid operating licence granted by a Member State in accordance with the provisions of Council Regulation (EEC) No 2407/92 of 23 July 1992 on licensing of air carriers(5);
(d) "tour operator" means, with the exception of an air carrier, an organiser within the meaning of Article 2, point 2, of Council Directive 90/314/EEC of 13 June 1990 on package travel, package holidays and package tours(6);
The airline has to fork over, and then, this will, likely, be dealt internally between the airline and the handler, respecting contracts or other policies.