First would imply a second. Since he was the only one who shot, there was no second shot.
Unless you kmean this:
![](https://images-wixmp-ed30a86b8c4ca887773594c2.wixmp.com/f/c988dcea-df7c-4024-bf40-499955a21409/de5gao7-10adf21f-90a4-4f15-9937-15c2bfcece74.gif?token=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJzdWIiOiJ1cm46YXBwOjdlMGQxODg5ODIyNjQzNzNhNWYwZDQxNWVhMGQyNmUwIiwiaXNzIjoidXJuOmFwcDo3ZTBkMTg4OTgyMjY0MzczYTVmMGQ0MTVlYTBkMjZlMCIsIm9iaiI6W1t7InBhdGgiOiJcL2ZcL2M5ODhkY2VhLWRmN2MtNDAyNC1iZjQwLTQ5OTk1NWEyMTQwOVwvZGU1Z2FvNy0xMGFkZjIxZi05MGE0LTRmMTUtOTkzNy0xNWMyYmZjZWNlNzQuZ2lmIn1dXSwiYXVkIjpbInVybjpzZXJ2aWNlOmZpbGUuZG93bmxvYWQiXX0.82knr0-FfrAlo9bQBAfUMIMJ3gS48lijDbKt0z1jZJ0)
Then, Greedo shot first.