Ha, you comical duo crack me up.
I suppose on reflection the pilot is ultimately responsible but alas he was assured by the constructor of this fine looking aircraft that she was correctly fitted out and ready for maiden.
Naturally the pilot would check correct control surface movements and if necessary introduce personal touches such as expo but I'm not sure if its the pilots duty to ask the constructor to go back home, bring the manual,to verify that the right amount of cells had been fitted when the word of the constructor was she was good to go. There is an element of trust I believe that still exists between modellers.
On the bright side you guys get to practice your judgemental air accident investigation visual skills and hopefully whilst at it enjoy some eye candy crash action.
All the best, respect