They may not have ever met directly. Given that Mr. Erickson appears to have gone to the trouble of investigating Mr. Condon's web of contacts as well, there might well be one last intermediary — someone who saw to it that Mr. Condon would wear the headphones. This person might subsequently have given instructions through them, or Mr. Erickson might have done so himself.

On the other hand, this information may simply represent part of the effort needed for him to arrange to meet Mr. Condon directly. If he managed to manipulate the right person, that person might have been made to introduce the two of them. It's hard to say which of these scenarios is the truth just yet.