Cali water is COLD.. I wish it weren't so cold or I would be in it a lot more. lol. So anything from the ocean in Cali will not survive in a normal tropical reef tank, temps are much too warm. Also, you may not want to post stuff like that on the internet.
Maybe speak in hypothetical terms next time instead of admitting you or someone you know did it, because I am pretty sure your brother broke some laws. You just never know who may be reading these forums.. not that I am someone you need to worry about, we all make mistakes and taking a few muscles means nothing to me, heck, my first SW tank was one my dad made by grabbing water out of the ocean and whatever he could grab out of the tide pools near where I grew up in the early 80's.
Personally, I wouldn't put those in my tank at all, not even as food. Muscles are one of the oceans filters, they grow in tide pools and on piers and suck up bad stuff out of the ocean, and on the coast of cali, there is a lot of bad stuff. I would think farm raised muscles you can buy at a seafood store would be much healthier to feed your eel and not have to worry much about nasties.