I have just been reading this: Jodi Arias Guilty Or Not Guilty Of Murder? You Be The 13th Juror (VOTE) ( David Lohr, Huffington Post, May 6, 2013 )

The article contains this paragraph:

"What is bizarre about some of Arias' claims is that they are irrelevant in the grand scheme.
Once she admitted she had killed Alexander, why argue about some of these little things?
In the case of her finger, Arias' version of events was an attempt to show prior domestic abuse,
but it might have served her better if she had played it differently. As for the gas can, what was
the point in saying she'd returned one and then being contradicted by a witness?"

When something seems "bizarre", that means you have not understood - it is cognitive dissonance.
A disciplined thinker looks for such dissonances, and explores possible reductions.
The correct reduction in this case is that Jodi Arias told the truth, implying that the
Walmart "expert" was mistaken, and Jodi's finger was indeed the result of domestic abuse.

Perhaps juror instructions should say "Do not return a verdict if several things seem bizarre or puzzling".

If you don't understand, that is reasonable doubt.

See also Walmart Return, Cognitive dissonance 101 , Fighting Cognitive Dissonance & The Lies We Tell Ourselves.