In some places bomb disposal technicians are only allowed on the job for a limited time. Then they move to the "back seat" and consult or assist from far away. Because with years of knowledge and experience comes the kind of confidence that doesn't apply well to unknown devices rusting in the ground for close to a century. Misplaced confidence is dangerous.
Does it work the same way in the UK?
Probably not. The article mentions two active bomb disposal soldiers whose rank is Major or higher, and a colonel who oversees operations. This seems like a standard military career progression, not specific to the EOD regiment. In the armoured infantry, for example, a company commander (i.e. a Major) might still fight as a dismount, delegating a sergeant to stay in their vehicle to command it.
Also note that in the British Army, soldiers of all trades often move jobs every couple of years, sometime returning to a particular organisation but now with a higher rank.