Happens every day in GA ops in Australia - particularly away from the capital cities. Anecdotal evidence reveals majority of GA pilots are very careful not to write up defects in the maintenance release (servicing document) unless specific permission from their management is received. The object being to minimise down time on the aircraft and associated servicing costs (transportation of engineers to remore areas where the aircraft might be stuck). The second objective is hide unserviceabilities from CASA inspectors who might be tempted to show more than a passing interest. Job security is another reason some pilots decide not to officially record maintenance defects. Don't make waves and we'll all be friends...