I got caught like this once. If you checked the forecast and it was Ok then you have done all that was expected.
While I know what you're getting at, I think that's a rather broader statement than I'd use. Weather forecasts
do go wrong, and it's important for pilots to take account of that. The key is always to have an alternative plan. In many cases for VFR flight, that's as simple as "make a 180 degree turn and head home" which is pretty close to what happened here. But it's always worth thinking through that possibility, and in particular the issue of fuel management associated with it.