A task, is an assignable unit of work related to meeting the software's (user) requirements. CIG is tracking bugs and outstanding tasks independently. More about that below. It's important to realize... the total number of bugs and tasks outstanding does not impede the software from being released. The release Go/No Go is hinged on the total number of outstanding bugs that exceed a certain priority. CIG has, it seems, drawn the line at "No Medium priority bugs", which is common among software products being released for the general public.
the "more": There's something though, in the numbers on the website. For example, the Missions Epic (or functional area) has 11 bugs listed, and a completion of 13%. That does not mean that 1.43 bugs has been completed. The way I read it, each bug may itself generate tasks, and of the tasks that these bugs generate, 13% are completed. There are 76 other tasks related to requirements, of which 66 are completed (rounds to 87% which is displayed).
So yeah, Nothing beer can't fix, but I'd say that coffee would be a better Beveridge for the development team. Or Red Bull. 5 hour energy... Whips and chains... oh. Never mind, that last part. Wrong kind of software.