No Good Way to Turn Left

What's wrong with this picture? Other than the fact it is a simplification of in intersection I travel through four days each week, ostensibly nothing is wrong [oh, except for the one driver encroaching into the crosswalk, of course]. It was only when the players involved were put into motion that the problem became evident.

I am in the vehicle marked 'C', a little way back in line, waiting at a red light. I notice a young woman ('A) on her bike to my left, on the sidewalk, opposite side of the street, and facing the same direction I am, well back from the corner. I wonder, if she is going to cross, why is she not closer to the corner? It seemed a little odd, but I thought, maybe she was not going to cross, but was simply waiting for someone. After about forty-five seconds or so, she kicks off and I begin to feel some trepidation. Almost immediately after she moves the signal changes, and the left turn lane where car 'B' waits gets the green turn arrow. 

"Don't do it" I didn't yell out. Sure enough, the rider, who is behind car 'B' (also now in motion and part way into its turn) and therefore out of the drivers' line of sight rides into the street (green turn arrow, but red walk sign), and proceeds to make (what in essence) turned out to be a left turn from the sidewalk. Luckily the driver of car 'B', though understandably not expecting anyone to be in his way during a dedicated turn time, used his/her powers of peripheral vision, and managed to stop before any damage could be done.

I was curious about the riders' thought process, and pondered it the rest of the morning. A non-citizen perhaps, and thus not familiar with traffic protocols? Perhaps from a country where bikes have their own signals, and thinking that the dedicated turn arrow applied to anyone making a left turn? Maybe just not very observant? Tempting fate? This could have turned out much worse. You don't make left turns from the sidewalk, you make them from the left turn lane.