I can understand why some stringers does that, on a basic or intermediate 72 holes racket, the most common stringing pattern is last string at hole 7 and tie off at 5.
This astrox 99 pro is slightly different, last string at hole 6 and tie off at 5. All racket is slightly different, a more experienced stringer would pay attention to new emerging patterns. Saying that, I made a similar mistake in the past but on my own racket as an amateur DIY stringer 
. Shop should not make this mistake.
