^if it wasn't during leave or their time off then they would have needed to get permission to go....and probably permission from the hospital too.

although if it took place at night they could have finished their day as usual at 6pm and then driven to Birmingham. it's only a little over an hour away according to Google Maps.
if they did take off work to do it i cant hold it against them considering what they were doing.

i remember reading somewhere that William and Harry would occasionally take off time from their military duties to preform royal duties/events.
thanks for finding the pic Kellyfan!
