Operating system: Win10 Pro
Graphics card: Nvidia 1080 GTX Ti
blender2.7, commit date: 2019-05-04 13:12, hash: d83a72ec104c
Short description of error
In Pose Mode, when clearing any bones' Scale Transform, via shortcut Alt-S that bones' Bendy Bones' properties of Scale and Easing are reset to 1.0 and 0.0 respectively.
This makes it hard to reset the whole armature easily, as each individual Bendy Bones' scale values X Y and Z have to be set to scale of 1 individually.
Exact steps for others to reproduce the error
The bone doesn't even have to have more than 1 segment.
In any bone's Bendy Bones property set Scale In/Out values to anything other than the default 1.
Set Easing In/Out values to anything other than the default 0.0.
In 3D view press Alt-S.
The values will revert to default after a short delay.