Albert Barnes Commentary 2 Samuel 19:18

"And there went over a ferry-boat to bring over the king`s household, and to do what he thought good. And Shimei the son of Gera fell down before the king, when he was come over the Jordan." — 2 Samuel 19:18 (ASV)

As he was come over Jordan — This means, “when he was crossing,” that is, just embarking for the purpose of crossing. The scene still lies on the east bank. Shimei left nothing undone to soften, if possible, David’s resentment.