Template assumes single supervisor and examiner. Most PhD students have two.
Template should have support for multiple supervisors and examiners, ideally by using something like
\supervisor{Ola Nordmann \and Kari Nordmann}
to produce
''' Supervisors: Ola Nordmann and Kari Nordmann '''
A possible quickfix is just to add (s), so it'd be
\supervisor{Ola Nordmann and Kari Nordmann}
to produce
''' Supervisor(s): Ola Nordmann and Kari Nordmann '''