Spectacular strikes from Graham Kavanagh and Paul Thirlwell secured League One status for the Cumbrians but Jackett was furious when Keogh brought down substitute Jason Price who looked to have a clear run on goal.
"It was outside the area but it should have been a red card," said Jackett.
"We hope to get a better referee in the play-offs."
Lions assistant Joe Gallen added: "It was a struggle for us. We had chances but the best team has won."
Source: Team_Talk