Maybe these two argument may console you:
1) It sadly fits Dean's character: "Never lucky....", "Always to late". But he may find a new partner regardless.
2) Depending on the outcome of most Path A and B Route, we can certainly assume that Dave and Dean will open a Coffeshop together regardless, by their own or even with Oswins Money (medal hunt). In a way it must happen, otherwise Dean will tragicly die by a work accident as Thanatos mentioend.