Collision Course (Part II) - S6-E9
Continuity mistake: When Mack and Davis slide down the rope, they're wearing gloves. You see Davis take his gloves off, but Mack hasn't quite started to when we see Yo-Yo close to landing. When the shot cuts, Yo-Yo is landing and Mack now has his gloves off as he draws his weapon.
Chosen answer: Coulson believes he was resuscitated then sent to Tahiti to recuperate. "A magical place," he calls it. But in the "Agents of S.H.I.E.L.D." episode "The Magical Place", Coulson, through a mind-reading machine, learns that he was treated by S.H.I.E.L.D. and a fake memory of Tahiti was placed as a "mask" of sorts over the painful memory of the operation, which involved a drug seemingly of alien origin to repair the damage, coupled with a lot of morally dubious surgery.