Earlier quoted context omitted.
Patrol ship sees and engages a foreign warship inside the patrol's territorial waters and radios for help. First fighter available launches and flies that way to investigate. Sees the warship engaged with the patrol boat and takes initiative, while other fighters are prepping for launch for follow on attacks in case the invading warship does not retreat or surrender.
The issue is "single". Does scrambling a single fighter ever happen, don't they always fly in pairs? A single attack or recognisance plane would make sense. Of course they might have known that their ability to properly identify the threat was limited, but that raises even more questions...
The USS Stark was hit by missiles from a single aircraft just a year before the incident in question. So no, they don’t always fly in pairs.