Bingo, having just left a mega-corp this is the status-quo of a lot of projects I had visibility into - take a trivial task, estimate it at 8-13 story points (i.e. the whole 2 week sprint), have nobody question the estimates, complete the story in 1-2 days and then chill for the other 8-9 days left in the sprint. It was pretty much an open secret.
...and nobody gets faulted by management, because they completed the story in the time they committed to.
On the other hand, if you had estimated the task at 3 days, and it ends up taking 5, you would get dinged for it. Estimate the same task at 13 story points, even if it was really only a 3, you were rewarded for meeting estimates - its a very perverse incentive structure.
Some high-paid consultants got paid a lot of money to sell it to the CEO, who then mandates it....so we are stuck with it ...until those same consultants have some other methodology-du-jour to sell.