Jet Flies On With One Engine Out on Nonstop Trip to London

"Mike Rapoport" wrote
I find more rational be believe that the procedure developed by BA,
FAA, JAA, Boeing and implemented by the crew was not a totally stupid
stunt than to accept your assertion that it was.

From the FAA:

Section 121.565: Engine inoperative: Landing; reporting.
(a) Except as provided in paragraph (b) of this section, whenever an
engine of an airplane fails or whenever the rotation of an engine is
stopped to prevent possible damage, the pilot in command shall land the
airplane at the nearest suitable airport, in point of time, at which a
safe landing can be made.

(b) If not more than one engine of an airplane that has three or more
engines fails or its rotation is stopped, the pilot in command may
proceed to an airport that he selects if, after considering the
following, he decides that proceeding to that airport is as safe as
landing at the nearest suitable airport:

(1) The nature of the malfunction and the possible mechanical
difficulties that may occur if flight is continued.

(2) The altitude, weight, and usable fuel at the time of engine stoppage.

(3) The weather conditions en route and at possible landing points.

(4) The air traffic congestion.

(5) The kind of terrain.

(6) His familiarity with the airport to be used.

(c) The pilot in command shall report each stoppage of engine rotation in
flight to the appropriate ground radio station as soon as practicable and
shall keep that station fully informed of the progress of the flight.

(d) If the pilot in command lands at an airport other than the nearest
suitable airport, in point of time, he or she shall (upon completing the
trip) send a written report, in duplicate, to his or her director of
operations stating the reasons for determining that the selection of an
airport, other than the nearest airport, was as safe a course of action
as landing at the nearest suitable airport. The director of operations
shall, within 10 days after the pilot returns to his or her home base,
send a copy of this report with the director of operation's comments to
the certificate-holding district office.