What I seem to understand and what you're missing is piping bleed air at potentially several hundred degrees into a starter on a multi million dollar jet engine that has a bolded limitation to avoid such activity past a certain point, be it time or turbine speed, aint gonna end well, either for your ride, and potentially the engine.

The caution msg you referred to above is actually referenced specifically in section 4 of the POH in the engine start section, where the related section starts with the following line: "It is imperative that starter cutout be observed at 50% N2," then proceeds to tell you exactly what to do to solve the problem prior to referencing the QRH / QRC should you see the NO STRTR CUTOUT or STRT VLV OPEN messages. It is a scenario that is usually covered in training while doing an external air start, but could also occur on an APU start. While perhaps what you say on your bust was maybe not exactly what you had seen in training, apparently the APD assumed enough transfer of information in other parts of your training had occurred that you would be able to respond well, not to mention the specific situation was referenced in the POH. I guess he was mistaken.

But hey, at least you have a cadence.