Well it does state:
"While we make every effort to ensure that this information is as accurate as possible, it is provided by third parties and we publish it as supplied to us. We are therefore not able to verify its accuracy or completeness and shall have no liability for any loss or damage incurred as a result of relying on this information. You must take appropriate steps to verify this information before acting upon it. It is important that you check with your airline to confirm your flight status. "
directly underneath the times. If the third parties don't update, then it's not the airports fault that wrong information is displayed.