Hayes is leaving to become head of comms at North Yorkshire County Council - a perhaps unlikely destination spoofed in a jokey souvenir pamphlet handed out at the bash.
The pamphlet - in the ABPI's distinctive font and bearing its logo - was badged 'A Manifesto from Ben Hayes: T'Right Job, T'Right County, T'Right Time.'
We found inside various light-hearted references to the issues with which Hayes has had to deal at the ABPI, such as its revised 'tighter' Code of Practice.
In a section badged 'Putting Hayes First', the joke pamphlet says: 'I have supported a further revision of the Code of Practice that adds the words "except Ben Hayes" to all clauses, especially those to deal with go-go dancers and bribes.'
Just goes to show that even the drugs industry's spin doctors can give their humour an outing when the occasion allows. Good luck with t'whippets, Ben.