In "Squeeze Play", why does the retired construction worker still drink at the construction workers' bar, let alone with his hard hat on? Seeing as Magnum had just gotten knocked down and trampled by the other workers, fights like this must be commonplace at this bar and the retired worker, still wanting to drink there, felt the need to protect himself.
If Higgins really is Robin Masters, why take a different name? Due to the more salacious content of Masters' novels, Higgins would likely do it to avoid embarrassment to his family and reputation.
In "Deja Vu", we learn that Duncan Scott is the head of an international group of killers who specialize in political assassinations.note (including Anwar Sadat in this universe, which ironically is a goof, as earlier in the series Colonel Ivan was implied to have done it.) On that logic alone, just how many more assassinations and killings is this group responsible for?
Similar to the above example, Colonel Ivan could have easily tortured and brainwashedmany more captives of his to be activated later as sleeper killers.
