I've been in this worrying position myself, wondering if there are fake bids.
There is an Irish Property Services Regulatory Authority; and it has a Code of Practice; more information with a link to the code of practice itself is [broken link removed].
As the site says, the codes or practice is 'voluntary' for now; auctioneers may or may not subscribe to the code--the intention is that they will be forced to subscribe in time. If they subscribe to the code, you can register a complaint against them if they violate the code. Further, "If you have a complaint, regardless of whether the Auctioneer/Estate Agent has signed up to the Code, you may still write to the Authority and register your complaint for future reference."
We do not know if the person in question is subscribing to the code of practice. I don't know how to find out if he is. The website can tell you of 'licensed' property service subscribers, but I do not know if that means subscribing to the code. Might be worth contacting the Authority to find out whether someone is subscribing or not.
Now, the code on section 1.9 requires him to "maintain a record of
all offers made for property, including the identity of the person/representative making
the offer, the level of the offer and any conditions attached". He must keep this for six years, to be available for inspection by the authority in disciplinary proceedings. He therefore is exposing himself to risk if he reports fake bids.
There are other things you can do to investigate. Do you have any friend, preferably a friend that the auctioneer does not know is a friend, who can call and make enquiries? If the friend gets information inconsistent with yours, that's obviously a huge alarm bell and a basis for a complaint.
However, if the friend reports the same thing as you do, it's probably genuine. The market response to any given property is full of surprises and unpredictability; it is not damning in itself that this reported bid on the property is significantly higher than what another similar one sold for. However, some of what you report does indeed seem quite odd, although secretaries can make mistakes, and confuse one property with another.
I hope that helps.