Is there any chance that that administrator has you in their webmail account? I know there was a couple of times where I never gave LinkedIn my webmail account

Is there any chance that that administrator has you in their webmail account? I know there was a couple of times where I never gave LinkedIn my webmail account details (though they do have my webmail address), and that certain friends showed up as suggestions from LinkedIn. The only thing I can think happened was they gave LinkedIn their webmail account details and from there, LinkedIn started suggesting them to me. This, obviously, is different from LinkedIn confirming I know someone. There are no other 'connections' between them and I. Zero. Either way, I was creeped out for a little while, then impressed :)