It is because the thigh bone is the active object, when doing box selection you don’t change that and it also becomes part of the selection… I don’t remember that being the Normal Behavior or not, I spend too much time using either the outliner or shift selecting.
If you box select over the cursor or origin point it will also select the active bone… and the objects that are in the box selection area…
There is another weird one, at least for me, Box select only the R-Finger Bones that have reversed normals…enter edit mode the thigh will also be included!
Look at where the origin is.
It is outside the object, but the origin is part of the object.
If you select the origin with a box selection, it is the same as selecting the object.
Damn, i think you’re right, i never noticed that if the origin was away from an object, you could select the origin and it would select the object!
Seems like a bit of a gotcha and would be nice to be able too turn it off in the settings (origins are easy to miss and when does one ever want to do that anyway?!)