Not saying I "know" that it works and I don't train this specific skill, but:
I've seen somebody break only the bottom or a middle brick in a stack of red house bricks by striking the top brick.
I have observed that strikes, depending on their speed, can either "push" or "penetrate."
The above example seems to indicate the ability to transmit force below the surface -- presumably to an inner organ.
So I don't know about "exploding livers," but rupturing an organ seems plausible in this way.
Of course, a hard enough strike can do so. I probably have told this story before, but there was a guy, Roger Stamp, who in the late '70s/early '80s sidekicked another fellow student, last name of Compas (I worked out with his son, Darren) hard enough to dislodge an organ. I think it was his liver.
He turned pale and my instructor, who was there at the time as a student, said he was going to call an ambulance. Mr. Compas said "NO! Don't! I'm OK!"
My instructor said, "If you can stand up, I won't call the ambulance."
He wasn't able to, and the rest is histor....er.. no video tape....
so the rest is "legend."