He stopped. There was a provision, often overlooked, for triaxial stress states. If he could prove that the triaxial strain limit wasn't exceeded, he could justify the localized yielding.
Choosing Division 2 is typically a business decision based on material savings versus engineering costs. ASME Section VIII Div 1 vs. Div 2 for Pressure Vessels asme section 8 div 2 pdf
"No room. The piping interferes."