My brother-in-law and his buddy caught a big squid on a fishing trip awhile ago. They fired up a camp fire and proceeded to cook the squid. Once it was done, the took a bite and to their surprise it tasted horrible. They said it had a flavor like urine(I'm not sure why they would know what urine tastes like but since your sense of taste is connected to your sense of smell, when they tasted it it probably invoked memories of the scent of urine).
My question is, what is inside the squid that is causing this 'flavor' when cooked and how do you prepare squid to get rid of this flavor?
update
The squid was Humboldt Squid (aka jumbo squid) ~5 ft long. They were caught live and cleaned, I.e. guts removed. My brother-in-law confirmed the taste as "tasted like piss". :)