It is the usual go around, panic, drama, omigod, we are all going to die scare that happens every now and then.
But I will say that it might have been a good idea on the part of the crew to announce the go around and the diversion. A courtesy to the passengers in fact. Also the delay on the ground at Shannon may have been no more than a wait while staff were rounded up to man the jetway or whatever. But again apparently no announcement was made. That to me is a basic lack of courtesy to the customers on the part of the crew. Simple as that. It takes nothing for a quick announcement on the pa.