The Kuwaiti was due to speak at Monday's event but failed to show, prompting an angry reaction from an already disgruntled fanbase on the social media site.
But Al Hasawi had a valid reason for not turning up - or so he says - and provided the photographic evidence to prove it.
I would like to clarify why I was unable to attend #NFFC's 150th anniversary gala dinner last night.— @FAWAZ_ALHASAWI (@fawaz_alhasawi1) 3 May 2016
I was attending to business in Kuwait and sadly my flight to the UK was cancelled. I was desperately disappointed to miss the event. #NFFC— @FAWAZ_ALHASAWI (@fawaz_alhasawi1) 3 May 2016
Forest's ongoing search for a new manager has only added to supporter frustration, following a dismal campaign which saw the Reds flirt briefly with relegation.
But Al Hasawi insisted the hard work is continuing, adding the candidates to replace Dougie Freedman are being heavily scrutinised.
The future of Al Hasawi himself remains uncertain, amid reports that Olympiakos owner Evangelos Marinakis is looking to acquire the Championship club.
Last week Al Hasawi posted a picture on Instagram which appeared to show him on holiday in Athens - close to the Greek champions' Piraeus base.
The 47-year-old arrived at the City Ground in 2012 and has gone through six permanent managers in that time.