I'm 100% sure you didn't think of what I'm about to say, so I'm not judging you or coming down on you or anything, but I thought this was important info to share.
What you did could have had very negative consequences for others, however unintended that would be.
On the way BACK to the airport, you are scheduled for a specific bus at a specific time. IF the bus you are getting on early is scheduled to be full, and IF you get on at the first pick-up, your presence will mean that someone else will not be able to get onto the bus. Again, if the bus was reserved to be full, and you are an extra person on that bus, that means you are taking up the seats of someone who NEEDS to be on that bus, who has a reservation on that bus, who may now possibly miss their plane because you stranded them at their resort for awhile until another bus comes along (a minimum of 30 minutes). And then if that bus isn't full but will be later, then THAT person will displace someone else, and so on.
Something to think about before attempting to get on an airport-bound bus that is not your own assigned bus.