Comment Re:Wow! (Score 1) 99
Obviously the defence didn't work in your story, but it may not be as flawed as you might think.
Depending on the jurisdiction (at least applicable to UK-based common law jurisdictions), there is a requirement to prove an intention to permanently deprive the rightful owner of the item, and as such an intention to return the item can allow you to wriggle out of the definition of the crime.
I'm not familiar with criminal law in the US, but I suppose the precise definition of theft various from states to states, so not sure how well this would stand in the exact scenario you described. Even if the jurisdiction adopted a similar legal definition of theft, the jury could still call BS.