Nearly all manufacturer's Fllight Manuals/POH have a definition of their requirements for "Land Immediately" or "Land as soon as practicable". I would have expected that to be the criteria?
Assuming you're training on a Robinson, Frank's definitions can be found on the first page of the Emergency Procedures, Section 3:
Land Immediately - Land on the nearest clear area where a safe landing can be performed. Be prepared to enter autorotation during the approach, if required.
Land as soon as practical - Land at the nearest airport or other facility where emergency maintenance can be performed.
On the basis of your description of the examiner's response, I'd say that his interpretation matches Robinson's definition quite closely.