I get head hunters calling me all the time. I think what happened was you got a new recruiter in the office that was given a list of phone numbers and names and told to start calling, since she doesn't have a client base yet. She probably had no idea it was your bosses phone. So I'm not sure I'm going to chalk this up to rudeness, but an actual mistake.
I wish I could chalk it up to a person being new because I have had that happen before too (that's a whole other story~almost got me fired!) but this time, she wasnt new, it was the same person that had placed me in the job (and I had given her my email and my cell phone back then because I didnt want to have job discussions at work). And, when she called during her requisite 'follow up' period, she used my cell phone number (that hasnt changed). So she definitely new better. she also could have looked up our general line (since she obviously knows where I work) and asked for me via the receptionist. Plus, I hadnt heard from them during the first holiday after I was placed, but suddenly, they want my updated info to send me a card this season? Not to be a brat here, but this was definitely unprofessional behavior.
Now, the other recruiter that almost got me fired - I wrote a letter to their corporate headquarters and the guy was let go (they had been having problems with him) soon after. I got an apology from them, but I stopped using their service, and requested that they stop contacting me. They complied willingly and quickly.
Ahh, the joys of using placement agencies...
Anybody else got a good story?