Using Entity Framework, I received a number of the following exceptions last night in one of my applications:
System.Data.EntityException: The underlying pro
My bet is that the success response from the transaction commit command was not sent (or not sent fast enough) causing an exception in your code. A kinda crazy edge case. Exceptions of this kind dont necessarily mean that the actual execution of the command failed just that there was A failure.
In the same way if there was a problem sending the response from a webservice call it wouldn't necessarily imply that any side effects of that call were not applied.