Ahhhh Thing... I still remember one now..... VC10 ( cannot remember the exact figures these days ) but it went like this...
No1 engine will not relight at 30,000ft
But is is not designed to, Rolls Royce say it will not normally light above 28,000ft, it is outside it's design parameters
But No2 No3 and No4 did
Best part of day wasted lix washing an engine even though it is doing what it says on the tin.