There is no good reason that a chip should have occurred in that area. It almost looks as if he pried the neck from the body. I guess the only positive thing to say here is that it is on the bottom side and you won't have to look at it EVERY time you play your new guitar. The neck unbolts and simply lifts off, with no glue involved. Granted the tolerances are tight, but there should be no need to force things. I once saw a neck reset demonstrated at a Road Show. It took about as long to remove the strings as it did to remove the neck. The factory tech took off the strings, unbolted the neck, and casually handed it to the shocked owner in front of the crowd, all while casually chatting about the process. Then he replaced the shims and put it back on, and restrung. That took a total of about ten minutes.
I'm sorry that you don't have many local options, but this guy would *never* see my guitar again. He clearly does not know what he is doing. You might end up sending it to the Netherlands to be repaired by competent people. Let Taylor in Amsterdam know all of the story just as you have expressed it here, including pictures. It seems better to have no authorized service center at all than one that will butcher your guitar. Lower the saddle first? Yikes! Clearly someone did not pay attention at whatever training was provided to get "authorized".
As for the action, it will get lower in dry conditions (the top sinks) and higher in wet conditions (the top swells). But that generally takes 2-3 weeks to become noticeable, not just a couple of days. When I lived in ultra-dry Alaska, many players had low summer saddles and higher winter saddles to avoid chasing the setup seasonally. It was challenging to humidify a case well enough to avoid that shift.
