estar and ser- re: fue in preterit

Hello, I was running through lesson 11.4 and noticed 'it was a very entertaining experience' used 'fue' to express 'it was'. Why is this not written as 'estuvo' since it is a temporary instance, as I was lead to believe all 'estar' conjugations were?

Hola. I don't feel confident enough when it comes to ser vs. estar to answer your question, but I do have a suggestion. A good place to ask if you don't get a response here is the WordReference.com forums. The main URL for the forums is __http://forum.wordreference.com/index.php__. If you join, then you can ask your question and get answers from knowledgeable people all over the world, many of them native Spanish speakers or English speakers with a strong knowledge of Spanish. Though I'm a member, I find that often I don't have to bother asking a question because it has already been asked (often many times) and discussed. So all I do is go to __http://www.wordreference.com/es/translation.asp?tranword=welcome__, choose English to Spanish or Spanish to English, and put in some key words. For example, I just did that, choosing Spanish to English and putting in *ser vs. estar*. The results appear here--__http://www.wordreference.com/es/en/translation.asp?spen=ser+vs.+estar__-- but be sure to scroll down near the bottom of the page where you'll see "Forum discussions with the word(s) "ser vs. estar" in the title:" followed by links to relevant discussions that have already taken place on the forum. The WordReference.com forums are absolutely amazing--far and away the best place I know to try to get information about Spanish. They may seem a bit intimidating at first, but the more you use them, the more I think you'll appreciate them. Finally, if you find some good answers to your question, I hope you'll share them here on the Rocket Spanish forum so the rest of us can benefit as well.