This didn't actually happen to me, it happened to a coworker. Where I work is a relatively new department of an established company (this may be relevant), and the manager is allowed final say in hiring and such. Because of this, and my manager being a generous person, my coworker was hired despite possibly not being the best candidate for the job.
My coworker was previously employed as an intern at a different organization and did not find a permanent role. They were then hired here. Sometime last week, a Recruitment Agency, who my coworker claims no familiarity with, contacted the main office of our company, asking for my coworker, despite him having a LinkedIn account with a direct email address provided.
This upset my coworker, who believes they now look unprofessional, and has upset my manager (albeit subtly). My coworker claims no contact with the Recruitment Agency, and I'm inclined to believe them (if you knew them you'd probably understand).
Is there potentially something unsavory about this, or could it just be a genuine mistake of my coworker or the Recruitment Agency? Is this some kind of common recruitment tactic?