Based on the last scenario given, it also appears the system generated the action vs. a human even 'contacting the buyer'. Now...as one who often lacks in administrative 'stuff' ---- I'd prolly be fired big time for not marking items as 'shipped'. Every other site that I use that has this feature - that feature is optional - not used as a measurement of nothing/nodda.
Yes - I felt the same thing! If there were a buyer complaint, by all means engage for resolution. But to redirect without investigation is just silly -

!!!