Yikes, what a jerk.

Really, there's nothing immoral about speaking to recruiters when you're employed. It's within your rights to know what's out there, and what your current worth is.

That said, I'm not a lawyer, but if you lose your job over this (and I don't think a reasonable employer should fire you over it), it wouldn't hurt to speak with one. The recruiter would have a hard time explaining his motives for pitching you to your current employer, other than incompetence or maliciousness.