My old job used to bring me into contact with many large financial institutions who broker deals. It's not exactly unusual for announced deals to fall through at the last minute, and certainly not regarded as unprofessional. The Wall Street Journal is full of prospective deals, mergers and acquisitions every day; many of which never come to fruition.
The club obviously thought they had a deal in place. It fell through so they went out and secured another one prior to the SPL kick-off. That sounds like good business to me and the sort of professionalism I would expect from a commercial department.