You just proved my point. You said you used leather laces from your shoes as cordage for the bow drill. I'm not saying it's impossible to use natural sources as cordage for a bow drill, but it would be extremely difficult to fashion cordage with the sufficient strenth and durability necessary for a bow drill without a considerable amount of experience. And it is very likely that the person swimming to shore would not be wearing shoes, either having taken them off intentionally, lost them in the water, was not wearing shoes to begin with, or simply not wearing shoes with laces. Creating cordage from clothing is not something the average person will know how to do, or even think of doing(and it is certainly possible that they would be leaving the boat naked). Then again, the aveage person will also have no idea how to assemble and use a bow drill.
It's also very different to use a bow drill that has already been assembled, after seeing the proper use demonstrated, than making one from scratch in the field. Bow drills also require very dry tinder, which may be unavailable.

And to answer your question, no I have not started a fire with a bow drill, or even come close. I have done some research and spent some time trying to build a bow drill, using para cord and various natural materials, and come nowhere near success (I do plan on figuring it out eventually). Granted I haven't spent all that much time on it, but the fact that I've been so unsuccessful even under ideal conditions shows me that making and using a bow drill is no elementary matter, and not something most people should depend on. In fact even experts would be foolish to depend solely on the bow drill as a means of fire making, in my opinion. I remember watching the video of 'survivorman' Les Stroud making a fire with a bow drill, and it took him hours. He made the drill from scratch except for his shoelaces, one of which he broke in the process. I don't know how extensive his survival knowledge is, but it's a hell of a lot more than mine.