I see lots of riders doing things I think are "pushing their luck." They "split" from the carpool lane by riding between the double-double yellow lines at all speeds. I have been run down by some heavy duty splitters. In fact, you have to check your mirror constantly before and while splitting.
Cars will move in and out of the carpool lane at any point - not just at the access areas. Whenever the regular lanes start to slow down - assume that someone (especially solo drivers!) will bolt into the carpool lane - that happens regularly.
I agree, I see a lot of "MC down in HOV lane" on the CHP incident reports. I guess it is mostly the riders "fault" for not anticipating the cagers bad behavior.
And then, many of the freeways in LA central are just too narrow to even consider "splitting." They are old, have bad surfaces, and just enough lane width to fit a car even though 25% of the traffic is 18 wheelers.
2004 dl650-the urban warrior.
2007 R1200RT - the highway beast