The seal bombs are a licensed and controlled tool. If the fisherman was properly licensed, there was no violation of the law.
Here is my problem with this....here on the East Coast...no need for "seal bombs". So if in your area on the West Coast this is a common occurance...even near the Golden Gate Bridge...why the need for the CHP, helicopters, FBI, governor, etc. And once again someone who is nameless and not caught causing a commotion. IMHO this "seal bomb" story is to cover for CHP activity at the bridge....something more "real" may have been happening.
BTW I like your story about your first hand experience with these, I never heard of seal bombs before....just goes to show you learn something new every day.
The fisherman may very well have legally been seal bombing. As a result though, it's evident since even the fisherman wasn't located, security for a renowned target is lacking.