So Not Dead

Two Kerrymen were working on a building site when one of them fell fifty feet from the scaffolding.
'Are you dead?' asked the first Kerryman.
'Yes', replied the second.
'You're such a liar, I don't know whether to believe you or not', said the first.
That proves I'm dead, because if I was alive you'd never have the nerve to call me a liar', said the second.