If you're asking that question re the cager, i couldn't care less about that dip sh*t.
Their reaction and loss of control to the boot appeared to be one of surprise leading me to think they may have been distracted as in texting or talking to someone on their phone..if they had engaged the bike earlier and been aware of a near miss, they would have had their eyes and ears on that bike for some time after.
The biker was probably pissed that the cager almost hit them and either didn't notice, or didn't care. Out came the boot.
I did smile a little when the bike just carried on. He/She/Non gender specific was extremely lucky in this instance they did not get killed or lose a limb on that jersey barrier.