Don't panic the poor man - the vast balance of probability points to him just not having closed the bolt firmly. This is not a big deal, it will not require a lawyer, it will not cause him to select a bad back stop, no one will die, no animals will suffer a slow and lingering death and he is not a bad person. It is a common thing to see on Blasers and almost anyone who shoots one for the first time does it. As with any mechanical device ranging from a car to a pen knife they are all different and there is stuff to learn about the particular model you happen to be using.
As Trufflehunting says in his sig line - keep calm and carry on.