To be fair, remember that they couldn't really scan the planet from orbit; so they didn't know what type of civilization they would be running into on the surface back when Pike and the 1701 first visited Rigel VII. And personally I think it makes pike look like a good captain in that he's more concerned about preserving the lives of the people under his command then worrying about Starfleet equipment.
And yes we all know that all Starfleet captains and crew members take a an oath that they'll die before they violate general order one AKA the prime directive; but we all know that in practice every Starfleet captain we've seen on screen has had an occasion where they decided to violate general order one to save their ship, members of their crew, or in extreme cases of themselves.
So bottom line, Pike's actions in the original Rigel VII visit are hardly outside the norm.