While it might be illegal, the flags hug the pier all the time. It is like speeding, illegal but mostly everyone does it. It is one of those gray zones. Now that there are no fishermen on the utmost point of the pier, it became even more popular.
PS: There is also no swimming next to the pier but everyone swims next to it. I'd think Sheriff's hands would get tired enforcing the rule. Plus, what is he gonna do? Jump in and dive or wait for hours for you to get out, hoping he got the right flag owner, as they all look alike..
I've twice seen divers get stopped by sherif while diving. Once, he waited till they surfaced, a second time he tugged their flag. So yes, like speeding and many other things, its all good and well until you get caught or hurt. Either way, you can choose what to do of course, I'm just putting the information out there for the OP.