I would suggest that there has been some selective use of the evidence put to them, in order to make a partisan point. I don't think that the choice of phrase 'more flexible' was sensible, in fact I think it was bloody awful as a phrase, but I can see the logic behind the idea that its much harder to retrain highly skilled and hugely technical people in one branch, and then expecting them to work at an equivalent level in another - its akin to asking a sea king maintainer to suddenly go and become a watchkeeper on a nuclear submarine. It could be done, but would take a long time to retrain to the necessary level. The majority of MOD CS have jobs which are more process based, and as such rely on skills which are broadly transferable, requiring less retraining time. If you can count blankets in one base, you can fairly easily stack paperclips in another.
I would suggest that a better phrase would have been 'MOD CS work in an environment where the majority rely on process rather than technical skills, and it is easier to transfer them around posts without extensive technical retraining or damaging career structures'.