Most awkward recruiter interaction was probably when I had to tell a staffing agency that I didn't want to work for them because I had already worked for them and left.

I got into IT by working for a staffing agency and I was contracted out to a large company's IT call center. Doing the usual sort of level-one tech support stuff. After my contract term ran out (and upon reminding my boss that she wouldn't be my boss for much longer if she didn't hire me away from the staffing agency), I was hired on full-time.

Six months later I left the call center and moved on to a cloud server development job in the same company. Not long after that, I got a message on LinkedIn from the staffing agency, offering to hire me on as a contractor working for one of their largest partners in the area.

I responded asking for more details, just for fun. The company I'd be working for, etc. Then I had to inform them that I had in fact previously worked for their firm, and now worked at the company that they were offering to contract me out to, and earning a fair bit more money than they were offering.

They didn't even look at my employment information on LinkedIn before sending the InMail. Just glanced over my skills, saw the magic buzzword "devops," and sent me a message.