c17age - Mr McN and I wore the same cap badge. The reason he and his patrol got caught is because the regt had forgotten the lessons of the regt's founders in 1942. Putting lads on foot on the ground in the wide open spaces of the Iraqi desert was asking for trouble. The later, vehicle mounted, patrols had far fewer problems.
I didn't say that fit people don't get captured, because they do, but unfit/fat people are more likely to get captured first/sooner. McN evaded capture for a long time, you will recall. A few of hours of freedom might be all it needs for a CSAR task to be successful.