It must be an error. The KO software doesn't even list a deviation for 10 vs 5.
It would take too negative a count not to double that. In KO full for 2-decks they show to not double a 10 vs 8 at -7, so 10 vs 5 would be even lower than that. Maybe someone can find the exact number, but I doubt you would ever use it, since you shouldn't be playing counts THAT negative anyway!