At the time, I did make the tough decision that first on the calendar wins (mainly because that was a quick and easy decision). Later, with some deeper thinking, I realised that the opportunity to engage with someone from an interstate plant about their strategic direction was a one off opportunity that I should have taken advantage of, when I looked at it from a Horizons of Focus point of view it was much more important than a regular health & safety meeting.
In hindsight, I think the real reason I missed out on the opportunity was because I tried to short cut the processing. At the time I found out about the opportunity there was still time to renegotiate the meeting, however I had several tasks and calendar activities on my schedule for that day, and comparing my calendar with this option I decided I really needed to focus on my calendar first, and would process it later in the day. Of course the calendar activities took longer than I'd thought and I didn't get time to process and renegotiate the committment. And in hindsight there was one calendar item I could have pushed back on which would have given me time to process and act on the opportunity. So this was a good reminder not to have things on your calendar if they can be pushed back, they do prevent you from having a bit of flexible time and being able to deal with things that arise. Also, processing earlier gives you a better ability to make good decisions about how to spend your time when your time is limited.