These things are becoming more frequent in the last time. There had been some border violation in the recent past by the German navy, but I didn't find that one to be as openly criminal as this here. My guess is that this will have consequences for the Adler company, and I would say that the warning shots were justified.
The Poles deny that they fired on the ship. I guess it´s not a Polish-German-affair but rather law enforcement vs. criminals.