Ceiling Joists have begun...

The framers showed up bright and early as usual and started constructing the ceiling joists.  They are framing up for the master bedroom tray ceiling and preparing for the greatroom vaulted ceiling.  Unfortunately, I got home from work and did my "walk around" and "picture taking" and noticed that they constructed the master bathroom ceiling joists for a flat 9 foot ceiling....it is supposed to be an 18.7 ft vaulted ceiling.  In doing my "non-professional" inspections, I have found several things that have been wrong and have needed to be corrected.  I feel so bad having to point out these things to Michael, who in turn has to point out to the construction guys.  They are really good about correcting things quickly, but I feel bad that they spend their time, energy, and supplies having to "re-do".  Maybe that's normal with house construction?  I don't know...it's the first house I've ever had built...