Did I reveal too much - have I stuffed myself?

[alantan]

They would be more subtle than that. If they have your CV then they have enough information about you to create a plausible story about how they "heard something from someone that used to work at x".

According to that most reliable soure, Wikipedia:

English law allows actions for libel to be brought in the High Court for any published statements which are alleged to defame a named or identifiable individual or individuals in a manner which causes them loss in their trade or profession, or causes a reasonable person to think worse of him, her or them.

Furthermore:

A private individual must only prove negligence (not using due care) to collect compensatory damages. In order to collect punitive damages, all individuals must prove actual malice.

An obligation for due care means that the agent is negligent if they are not in prior possession of evidence (in written or other physical form) before passing on the information (unless the information is actually truthful). It is not enough to employ hearsay in order to make false claims about someone without being liable in the eyes of the law.

[BolshieBastard]

We all do it from time to time but really, never ever, inform any agent, except the one you're working through, of any interviews, when your current contract runs out or renewals at your current assignment.