Dear me, there are some short memories around here.
The SAS almost certainly WOULD wait this long as there was no immediate danger to local inhabitants (already evacuated) nor hostages.
In case anyone has forgotten, this is the reason that anti terror units do not rush in all guns blazing unless there is immediate danger to life. As this man was already known to be heavily aremd, who knows what else may have been contained within the aprtment?
Watch the vid from 5.32 to 5.40 of what happened when some of the Madrid bombing suspects were holed up in their apartment as the net closed in around them: