Bad DPEs and bad pilots, same same. The checkride is to assess safety. If you don't qualify due to lack of hours etc. that is one thing. If you have typos or missing info, then its a discontinuance to get it fixed.
This also applies to the flying. if you come up consistently short in regard to PTS standards on a few things, a discontinuance is called for till you correct them. If you are a total mess on most of it, then a fail.
Sadly, the entire thing is subjective. So picking a fair DPE is the key. If this guy took your cash and you only did part of the checkride, then you should get your money back and use someone else, if he won't give it back, then pursue it by all means at your disposal. Don't let him steal it.