This is normal.
Your bike will compensate for any modifications you do to the bike ie. exhaust or filter will not change the mixture.
As noted here in a number of posts - BMW and other manufacturers run their bikes quite lean - in my experience BMW has always done this. Mainly for emissions regulations and pollution control.
One of the reasons some use "booster" plugs and such to trick the bike into running a bit richer. Again posted on here quite a bit.
Do not worry - and if you are really concerned take it in for diagnositics and they will be able to tell if all is well pretty quickly.
As your attorney, I advise you to buy a motorcycle. How else can we cover a thing like this righteously?