This Bible contradiction is from the Skeptic's Annotated Bible.

Verses

He hanged himself.

Matthew 27:5 View context

And he cast down the pieces of silver in the temple, and departed, and went and hanged himself.

He fell down and died.

Acts 1:18 View context

Now this man purchased a field with the reward of iniquity; and falling headlong, he burst asunder in the midst, and all his bowels gushed out.