BS (!)
The Capt set no precedent at all... It is no "secret" at all that for a number of BA 4 Eng ac, and same for other European carriers, equivalent sitations have occured in the last ~5 years:
- Another LAX -> LHR, Eng Fail before 5000', made LHR
- South America -> LHR - made LIS, enough for another company ac to be in LIS to take PAX onwards, and had a 3 Eng Ferry crew to get ac to LHR
- MUR -> Paris - nearly diverted NCE, but made Dest
There is a section in the Ops Manual exactly covering the Eng Fail situation, and the options available. This crew, as others, followed the options available as they saw fit
What followed at MAN was "another event", again followed according to conservative "best practice"