Is it possible that by knowing less about garbage collection in Java this person might have arrived at the same solution earlier? After all his initial construction of a tracing garbage collector was wasted effort.
Except, if someone want to pay Grug to work on garbage collector for javascript framework, Grug put in position where Grug learns what Grug don't already know about it because it now Grug's job. So Grug understand why Sun solve problem, why problem hard, tell other Grug about isomorphisms between spanning trees. Now other Grug know more about what other Grug don't know, why other Grug not make same mistake of knowing better than Sun Microsystems either.