Swissair 111 is a frustrating example. For some reason, a large amount of pilots do not understand why we dump fuel. I don't have any comment whether safe landing would have been possible, but anyone dumping fuel when you are on fire should spend some time understanding why we have the option to jettison fuel.
The only reason plane has to be able to dump fuel is engine out go-around performance. Halifax is a short-ish runway, but seeing how some dump fuel on short final to LAX tells me those pilots had no clue why you dump fuel.