You're thinking right.
There is no reason for any of this oil to have reached shore.
As to the leak itself, Other countries have had such leaks - and STOPPED THE LEAK. All these people seem to be concerned about is capturing as much of the oil for themselves as possible. (And Obumbles, has been, after all, the largest 'giftee' of BP contributions for some time. The media keeps side stepping this.
http://www.reuters.com/article/idUSTRE64420A20100505
Russia, with a small nuclear device, stopped two such leaks.
With all due respect, I am calling you on your claim that you know what is going on with that casing and the seafloor stratigraphy and stability, enough to claim that others have had such leaks.
As for Russia, I know of their gas-well nuking claims (and 1 in 5 failure rate), but haven't heard of them nuking two deepwater oil wells. Please provide sources.