Back in the day we were 'flight testing' the MD-11 after Heavy Maintenance and the checklist required Engine shutdowns and re-starts. We trained the whole profile several time in the SIM. We were at FL 300 and briefed sequences; Eng #3 shutdown, re-light, followed by #1 and so on. After the Co-Captain shutdown #3, we awaited the spooldown until we could re-light #3 by means of a windmill start. With sufficient N1, the Co-Captain switched "FUEL ON" and while we monitored the N2, Oil Px, EGT and FF within 120s, the Co-Captain shuts down ENG #1 without calling it out...we looked at each other WTF? We could not kept altitude with only #2 running and #1 spooling down and #3 accelerating and had to call ATC for an immediate FL change...If something can go wrong, it will one day.