It was expenditure like this that made scandals in the UK a few years back over which a lot of politicians were forced to resign and/or face legal trouble over the issues. However when expenditure like this exists within a company, it's rarely found out about and if the issue arises the company wants to brush the issue under the rug. Bad expenditure like this often is a sign of a non-existent or incompetent middle management.
Its good that is the company and not PHB who has to pay for the trip.
If it where government I would bet that PHB had a surplus budget that he wants to burn. Otherwise he would not get the same budget next year. A sad reality of all governments, efficiency is punished while inefficiency is rewarded.