QF international flights are equipped with extensive medical kits with quite a range of diagnostic equipment and drugs. From the sound of it (and this is based on the information provided here) even if medical volunteers onboard had been called, it wouldn't have warranted a diversion. I can see both sides though in that you would expect that the crew would call for medical volunteers, give them the medical kit and go from there. In the same token if someone presents with a history of intoxication and then complains of dizziness, sedative effects, headache and vomiting...

It can't hurt to email them and let them know of your concerns. I wouldn't expect anything except an apology, but I would say behind the scenes it would cause them to send a reminder to crew to follow whatever internal policy they have in place for when a passenger complains of being unwell.