The occasional wiring error on a "professionally built" panel is quite common.  I'm not sure how they do their testing, but some mistakes can slip through.  I've worked with a couple panels at my home airport, recently one from Aerotronics.

 

I spent almost a day tracking down a fuel gage problem.  I started out thinking the builder did something wrong (which is probably the case more often than not).  I isolated the error to be in a connector.  So I checked the side wired by the builder, fine!  I finally traced it to a pin in the wrong spot in the connector from Aerotronics.

 

That's not to slam Aerotronics, they do fantastic work, but not perfect work.  Maybe they had no way to test the fuel gages since they were provided by the builder and were not supplied to Aerotronics.  But there still was a pin in the wrong position, different from the schematic they created.

 

A fuel gage problem is not quite the same as the gear retracting however!

 

Mike Easley

Colorado Springs

Super ES