I think this is all a good illustration of why "Bob" was (supposedly) fired at the end of the story. A good sales engineer knows a lot about the product within

I think this is all a good illustration of why "Bob" was (supposedly) fired at the end of the story. A good sales engineer knows a lot about the product within its normal operating envelope, but especially knows a lot about the boundaries of "normal operation". Bob's very first response to "can this thing do a thing [that Bob should know is outside of its normal operations]?" should have been to go ask the kind of engineer who is involved in defining "normal". And either the capability is investigated (and, if plausible, eventually a "safe" demo is put together, and maybe the definition of "normal" is expanded), or its revealed that it won't work, and that's that. In either case, the rest of the situation never happens, provided Bob is actually good at the engineering side of "sales engineer".