I think that's what he meant by "[...] if I had looked at Dijkstra’s shortest path algorithm and breadth-first search one day before my interview, this would have been a trivial problem to solve [...].".
Sure, BFS is 'easy' but it's not really something that stays fresh in your memory after years of not having to use it.
I completely agree with his point that it if you have to study for an interview, the process is broken.
I mean... I'm 17 years out of college and I remember it. I don't have an implementation that I can just write out from memory or anything, but I remember the basics of how the algorithm works and I assume I could come up with an implementation that works.
