We know from past history that the sea cows were carefully created in Pinewood studios from foam latex and then flown by helicopter to Ireland, where the main sea cow and two smaller background sea cows were constructed.
As you could imagine, security was obviously displeased and rushing around to rectify the situation.
It was an ordeal and hassle to get them to the filming location and then to have to deal with factors outside their control I’d guess had to feel a little bit ridiculous.