All it means is
a couple of people (and it could be anyone within the organisations) sent an email to, at a guess, firstname.lastname@example.org asking if they'd be interested in making a bit of money. Liberty doesn't have to have received the email - and if it was sent to a made-up address, it's likely they didn't - for the story to be factually correct.
However, if this is the case, the story boils down to:
- someone sent an email, Liberty didn't receive it, nothing happened
which obviously needs a bit of sexing up (as only newspapers know how) to make it into the Observer and for it to be followed up to get even more mileage out of a bundle 'o nothing. One presumes that all the other scoops, investigations, special reports and exclusives these journos churn out on a slow-news week are equally substantial and prepared with the same amount of care.