The Privy Council Office is governed by Treasury Board directives on travel, as are all departments. Ministers' offices are governed by the Treasury Board document for spending in ministers' offices.
I have no knowledge of the particular case you are speaking of. I will be happy to see what I can find and do any specific follow-up.
One of the particular features of the Privy Council Office is that we support a portfolio of ministers. They have pretty rigorous schedules and are often called upon to do things at the last minute. We work within the rules to support them, so that they can do their jobs.