I am having difficulty understanding the exact meaning of 'full credit'.
Full Credit means they are exempt from doing a PPL course of Training. They are only required to pass a Skills Test (of course some training may be necessary/beneficial prior to Test).
Partial Credit means a reduced hours PPL course of training would be required.
However, I accept Whopity's statement that no such credit has been negotiated.
Which means your candidate would not be eligible for Test unless they had at least 45 hours of instruction/supervised solo from an EASA Instructor (am assuming a Part-FCL Licence) which included flying all the exercises in the PPL syllabus - and, I would guess, would also need valid passes in all theoretical knowledge exams.