User blog comment:EmpyreanSmoke/How did Cas survive the fall?/@comment-11331875-20150711011429

Metatron directly teleported Cass to Earth, thus avoiding the now-mortal Castiel crash-landing and dying in his human body. In Castiel's quote, he was referring to his metaphorical fall of when he lost his grace, and how difficult human life was for him. In Sam's quote, Sam wasn't aware that Castiel had lost his grace or that he'd been teleported to Earth by Metatron, so he assumed that Castiel had literally fallen to Earth with the other angels.