Seems like the military hasn't changed much over the years. Blame the lowest rank possible.
Here's how the song got started:

scene: Office of the Naval Investigator

Okay lets see….
We need to hold somebody accountable for the sinking….
They're starting to doubt the sea monsters since no-one has actually seen one,
It really was the Captain's faulty seamanship, you can only hit the sandbar so many times before something gives way, but since I gave him the job to get him off my staff, It'll be my ass in a sling.
I can't blame the Mate, Mummy would never forgive me for getting cousin Barty in trouble.
Can't blame the carpenter, everybody knows he died last year and hasn't been replaced yet.
The cook? No, I've been trying to shanghai him for my staff, that wouldn't help me get him here.
The crew? Whoa no! Not going there! They're the scurviest bunch of pirates I've ever had the mispleasure to waylay at the pub. They'd probably cut my throat if I blamed them.
The cabin boy? Yeah! That's the ticket. He's harmless, came from an orphanage, nobody will take up for him!
Now, how did he do it and why?
Ah to hell with it! He was mad at the Captain for stealing his girl and he used a ships awl to drill holes in the hull.
There, the reports finished. Now I can get down to the pub early!