Look, they're estimates . . . often made by other people than the ones doing the work.
(Oh, and having the build break for two or three weeks running didn't help the "estimates" very much. A culture of build breaking just rewards the people who are less careful than others).
I finally got the PM on our project to call our scrum meetings "status meetings" instead, because that's exactly what they were. Status for rollup into the Great Burndown Chart.
Over two years out of that garbage and I'm still bitter.
When you hear the words "Yup, we do Agile, but we have our own take on it," run away, because it's going to suck hard.