Agreed - maybe one of the least fathomable. Here this man, who looks more powerful than anyone on the Enterprise, he comes from Earth's 'barbaric past', and here you are giving him unfettered access to your tech manuals?
TWOK was pretty dumb too - First of all, you get an obviously jammed message from the science station which is working on THE most secret project in the Federation, and then an obviously out of place (even SULU says "Reliant...here???) Federation ship conveniently having communication problems shows up directly in your path to that station??? Even a fresh out of the Academy Lieutenant knows something is up!
Yeah but Sulu is also surprised when Spock shows up in Star Trek 1 when hes supposed to be on Vulcan and they dont just shoot him. Besides, Reliant was known to be doing business with Regula 1 and its not inconceivable that they could run into it. For all Kirk knew, the station was attacked and Reliant survived and was trying to warn others. He did kick himself later though.