It's normal. They all leak a bit. Mostly it's feathers, rather than down, as the ends of the quills poke through the stitching and work their way out. Since the only reason feathers are in there in a down (as opposed to feather and down, cheaper and not so good) bag is it's impossible to mechanically remove 100% of them from the down it's not something to worry about.
There's actually quite a lot of down in even a light bag, and while the leakage looks worrying in practice it's not, unless you have a seam rip a bit and let out lots.
Pete.
and on opening it, found some loose bits of down floating around inside. I have checked all the seams and can't immediately see anything wrong. Is that just something normal from the production process?
