I had to read the article to check the context - so glad you posted the link! In this context, "shoot" is used as an exclamation to express surprise. I expected to see an "!" after it so it is being used in this article ironically. We don't use shoot "in this way" in England. It may be exclusive to the US. It may be a tricky word to use in this context if you're not American - I wouldn't risk it myself! Michael

It means "what a shame", "oh no", "drat", "gosh darn it". Maybe it's a politer form of "oh sh*t" !

It means "Wow." or like 'so close.' If you kick a football and miss the net, you might say it. It either means "wow, this is great" or an expression of disappointment like "ah come on! really?". In this case, it the dissapointment from being so close to achieving something, only to have it not occur.

It's like saying "darn it". it's just an interjection or exclamation.