You people who think LA could run a 2H20 marathon, but no way a 2H15 one have absolutely no clue, and have probably never ran the event.
This is not such a huge gap, and elite runners very often bridge it in the space of 6 months one race. For LA, breaking 2H30 would, in my opinion, be much more of a barrier, as it reuires learning proper pacing, learning to deal with 'the wall', running specific training principles... etc. Once you've broken 2H20, the next barrier comes in the region of 2H12 or so...
Here in Europe, you easily notice that there are very few guys between 2H20 and 2H12. It's a sort of no man's land, which can easily be explained as it sort of marks the boundary between the keen amateur, and those who have chosen to make a career out of the sport... Sure you find guys running 2H17, 2H15... etc, in major races. But most of them will already have run 2H12, or will be on their way there (of a similar standard in the shorter distances).
If LA ever runs sub-2H20 (i.e. if he finds the motivation to train to achieve these sort of times, and is able to sustain it) then give him a year or two and he will run close to 2H12. The question is why should he? He might train for a marathon just to complete one (and his race inexperience will probably show (again, pacing will be the major issue in my opinion), and in all likelyhood run between 2H30 and 2H40 if he is serious about it. But after that, why carry on?
I somehow can't imagine him wanting a new career as a runner...