In Texas you can use deadly force to protect property. Cite:
http://www.capitol.state.tx.us/statutes/docs/PE/content/htm/pe.002.00.000009.00.htm
I read the statute. It is different than many jurisidictions.
However, I do not agree at all with the guy shooting the repoman as being justified. The person was a deadbeat bum and was not protecting his property. Its the bank's property until the debt is paid.