Is it fact or legend that Tommy and Liam Clancy were kidnapped by the IRA who tried to extort them into taking a political stance tha was beyond their principles? As I heard it, as a warning or threat of worse to come, Tommy's left index finger was broken and healed straight so he couldn't use it to play.

In later performances preserved on tape it's clear that that finger is sticking up and he's using fingerings without it.
Can anyone verify?