Might mean nothing, but Coulson (“His first name is Agent!”), in reference to his recovery, said (what I recall to be) the exact phrase in (what I recall to be) the exact same manner and tone of voice, at least twice. (paraphrasing now: ) “Tahiti is a magical place.”
Might suggest implanted memories, a phrase “activated” by someone questioning his convalescence in “Tahiti”, Coulson was actually enamored with Tahiti, or he himself knows where he recovered, but is sticking to the cover story, as that location is classified.
Because of what Maria Hill said to the whispered question (from Ron Glass?) of “He doesn’t know…?”: “No, and he can never know.” – seems to me that Coulson remembers his recovery one way (for whatever reason he remembers it the way he does), while the truth is something that would upset him or perhaps let the cat out of the bag on something very, very, VERY Top Secret.
We knew that the show would need to address Coulson’s resurrection, rather than just ignore it. Hand-waving would’ve been dissatisfying. Giving us a reasonable explanation that was hinted at in the Avengers movie is a good step, but then showing us that explanation very possibly covers up a mystery is a better step.
I’m sure somewhere down the line, Coulson’s recovery will be more directly addressed, but I don’t see it as being a part of the team’s normal storyline. In fact, thinking about it now, I’m not sure that revealing the mystery at any point would add to the storyline. No matter how they (further) explain it, I’m sure some portion of the audience will feel cheated and/or disappointed.
Complete turn into left field: I like that they showed Ming-Na’s character as apparently in the mold of a Black Widow-type: nearly the same type of catsuit, similar fighting moves, etc. Natasha may be the first to call herself Black Widow, but her particular skillset isn’t new to SHIELD, nor should it have been. Neat.