The replacement Referee got it very wrong indeed.
The stoppage when the original Ref went off was approximately 6 minutes - despite whet the Official Site says, given the need to (A) assess whether Mr Harrington could have carried out the fourth officials duties and (B) Having decided he couldn't locate a replacement, not an inordinate delay when there is a need to transfer data from notebooks, get the original fourth official warm so that he doesn't injure hisself etc. The officials stopped their watches at the point of the injury.
I always start my watch on countback from 45 minutes at the initial kick off of each half so, when 45 minutes had elapsed in the second half (I didn't stop my watch for the injury) an enquiry was made of the nearside assistant as to how much time would be added on.
The reply was "There's six minutes of normal time and then he'll be over" Six minutes or so later the replacement Ref came over and said that there would be at least a further eight minutes which Andy put up on the board.
Obviously this was wrong as the stoppage for the Ref's injury was accounted for twice.
Fortunately neither side scored during the incorrectly elongated stoppage time.
See I don't always defend officials and the guy tonight did drop a huge goolie