I think you're using a very narrow definition of coronation
You've effectively defined a coronation to be winning the popular vote in a totally open field. The inability for competitors to succeed doesn't mean he's fucking coronated. Getting 150,000 supporters out of nearly 300,000 isn't the same as winning a delegate vote with 2100 delegates while being interim leader as Ignatieff did. Even so much as drawing a comparison is nonsense.
When Justin/ Martha/ Joyce lose in 2014/2015, they won't be tossed out largely because nobody who was around for Martin, Dion, and Ignatieff are in the party anymore, and the changes to campaign finance by Harper have effectively castrated centralized control as well. People like Murphy, Rossi, and Apps are hasbeens, get with the program.And if Justin loses in 2015? He'll be out just like every other Liberal leader on the losing end of an election. No lessons have been learned and only a massive dose of party kool-aid can keep that fact from sight.