[Grammar] disappointed in/by

[ShirleyLing]

http://www.nytimes.com/2011/04/01/nyregion/01discrim.html

In a statement, an appeals lawyer for the city, Julie Steiner O’Donnell, said, “We are very disappointed in the court’s decision and in its interpretation of the N.Y.C. Human Rights Law.”

http://www.nytimes.com/2011/06/01/nyregion/accuser-in-nypd-rape-case-says-she-is-devastated.html

Five days after two New York police officers were acquitted of rape charges, their accuser broke her silence, releasing a statement in which she said she was “devastated and disappointed by the jury’s decision.”

Are there subtle differences between "disappointed in" and "disappointed by" only known to native speakers?

 

[5jj]

There is no real difference between 'by', 'at' and 'in'

Personally, I use 'disappointed in' when something or someone has not come up to my expectations over a period of time, and disappointed 'at/by' for a more immediate let-down.

I am disappointed in my flowers thiis year. I had hoped for a much better display.

I was disapponted by/at the final score. I think we could have won by a much wider margin.


However, others may not agree with me, including, it appears, the writer of your first sentence - I would have used 'at or 'by'.