I can see both sides but it depends on the position. Was he interviewing for something like a Sales Engineer role or strictly a technical role? If you're doing Sales Engineering or going for a Solution Architect on a PS team then sales is part of the role. If it's strictly a technical role that is not a part of the selling process then it doesn't make much sense to me.

/edit: now that i think about it, they may prefer a sales mindset in all roles which i can also understand