That is the kind of salesman no one wants to deal with, if their IQ is over 70. The last electronics 'salesman' I worked with would visit both engineering and production test to see what was going on, and had started with the company as a tech. If he didn't know the answer to a customer's question, he knew who to call to get the right information.
Your 'sales guy' should have gone back to selling used cars, or to putting lids on drinks at McDonalds.