The term gybe and execution of 'only a gybe' might not involve a course change. I can tell you it doesn't, like tacking, imply any minimum course change. When going from a beam reach to beam reach on opposite tacks you could either head up and perform a tack or bear off and perform a gybe.
While your manuever did not include only a gybe ... it certainly did include a gybe.
1981 C&C 32