I had the same experience with a recruiter for Google. I mostly have game design and production experience on my resume and since my background is in engineering, those skills listed as "side" skills probably matched his keywords. I didn't realize that at the start of the interview and was wondering why would Google be interested in a game designer. The conversation went on for at least quarter an hour, he was asking me for my experience with different software development platforms and I kept wondering why does that even matter. At a certain point I realized what was going on and said "actually I'm not interested in a software developer position"; his tone immediately changed and he quickly wrapped up the call after that.
I was wondering if my resume looked like an engineer's and went back and looked at it - nope, it didn't, at least not to me. I was getting software developer position offers every once in a while so eventually I added "Please do not contact me for positions in software engineering" to the "contact me for" part on LinkedIn. I still do get these from time to time