Interesting story - I have no idea about its veracity (or otherwise). I am currently reading the "Haynes Manual" book on the Vulcan and the authors (including ex Vulcan aircrew) reckon that 4 rear crews dies because they did not have time to do a manual bale out - that's 12 men dead because they didn't have ejector seats.
On the other hand I do remember some of my QFIs (ex-Vulcan chaps) telling me that they used to put their pins in the seats when doing ultra low level work - on the "we all go in together" principle.