This has happened a couple times to me so I do not think it is random. In the main quest rescue of Abner Tharn when I get through the portion where Caldwell tinkers with the three steam generators to open the door to the castle, I click on the door I hear the voices discussing Tharn from the cultists.
When the loading screen appears it takes at least 3 minutes before I appear in the next room. The circle in the lower right corner keeps rotating.
Not a game breaker but definitely odd.