Cobra Plot Holes

Plot Hole: At the end of the movie, Cobretti impales the Night Slasher with a large roaming hook through the Night Slasher's back. To make matters worse, he then presses a lever which moves the crane hook into some sort of furnace where the bad guy is literally burned alive with a massive crane hook sticking through his back. Afterward, Cobretti walks out of the building, punches out Detective Monte, and then hops on a motorcycle left behind by the bad guys and rides into the sunset.

Why it doesn't make sense: After putting a massive crane hook through the Night Slasher's back... he burned the Night Slasher alive. Once the hook subdued the Night Slasher wouldn't burning the man alive constitute excessive force and/or murder? There is obviously no way that Cobretti can justify burning the Night Slasher alive after he was already subdued.

Plot Hole #2: Also, wouldn't Cobretti punching out a detective in public in front of dozens of witnesses lead to Cobretti either being arrested for assault and battery or at the very least placed on a leave of absense (aka suspension)?

Plot Hole #3: An officer would never be able to murder a criminal and then simply drive away without ever explaining himself. At the least, Cobretti would obviously have to write a statement immediately.

Plot Hole #4: On top of that, he drove away on a motorcycle that wasn't even his, it was one of the bad guys. The motorcycle he rode into the sunset on would be considered crime scene evidence, and him driving away on it would be considered tampering with the crime scene aka obstruction of justice and grand theft auto. It should be noted that Ingrid hopped on the motorcycle with Cobretti. The relevance of this is that by going with him Cobretti could be charged with a 2nd count of Obstruction of Justice because he is technically preventing her from giving a statement.

Humorous Note: The ending of the movie saw Detective Cobretti committing at least 6 crimes himself (Excessive force, Assault and Battery on a fellow officer, Grand Theft Auto, and at least 2 counts of Obstruction of Justice because he tampered with the crime scene by taking a motorcycle and he took Ingrid, an eyewitness with him which prevented her from giving a statement herself). Some may try to argue that because he being an officer means taking Ingrid with him was not Obstruction of Justice; however, because he was involved in the incidents himself then he cannot conduct the investigation into what happened because it's a conflict of interest.