It was a long trip home for the Welsh fans after the single goal loss in Kent.
And Jackett apologised to the Swans faithful after the poor showing at Priestfield.
He said: "There were a number of supporters getting wet watching a poor performance so I have to offer an apology for that.
"We have two finals next week. I don't use that as an excuse, but we did look lacklustre.
"I've talked long and hard about focusing and I didn't think we prepared and played properly."