...I disagree that the immediacy of necessity isn't there in the OP's situation...let's forget the self defense law which would also justify him and concentrate on what he quoted...PC 9.42...which, word for word, spells out that immediacy of necessity in this scenario...
...this law clearly tells us under what conditions we're justified BY LAW in using deadly force to protect property...if we go through the law and it fits our situation, we're justified if we CHOOSE to use deadly force...
9.42 says he is justified:
(1) if he would be justified under 9:41(which he is) AND
(2) when and to the degree he reasonably believes the deadly force is immediately necessary : (B)to prevent the other... AND
(3)(B)the use of force other than.......follow through those sections and he is justified by the clearly written law...
...it is necessary to use deadly force to prevent an ARMED robber from fleeing immediately after committing armed robbery and it's reasonable to believe that the use of force other than deadly force to protect or recover the (property) would expose him or another to substantial risk of death or serious bodily injury...he, still being armed IS STILL A THREAT as you pursue him to recover your money as the law specifically states...
...if, on the other hand, the law said that you could not legally pursue him in an attempt to recover your property, then you would not be justified in using deadly force, and that part of the law wouldn't be there...but it IS...because you DO have the legal right to go after him as he IMMEDIATELY flees after having threatened your life with a weapon and robbing you...
...this process has been used many times to justify the victim or someone acting on his behalf IMMEDIATELY AFTER AND DURING THE FLEEING from an armed robbery...NOT days later...not hours later...but immediately...I have never heard or read of someone being indicted for shooting an armed robber in Texas during or IMMEDIATELY after the robbery...and meeting the requirements of 9.42 to claim this justification...
...the deadly force laws are written primarily to explain to us under what circumstances the use of deadly force IS LEGAL...so that we don't use deadly force in an illegal manner...rather than listing the elements of an offense, they list the elements that must be present in the situation for us to be justified if we use deadly force...
...NOW...if someone ran up to me and snatched the gas money out of my hand as I went to pay, or grabbed my shirt pocket off and got my money...and ran...I would not feel that it was either reasonable or necessary to shoot them to stop them...let's say, as the OP did,for a small amount of money...a human life is worth more than that money...though that, too, would be a robbery...
...BUT, if that same person came up to me and threatened my life with a gun or knife, took the same money, and turned to go, I would use whatever force to stop a still-armed and dangerous robber from escaping...if I could safely do so without endangering bystanders...the difference being his having threatened my life with a weapon and leaving to (as any reasonable man would think) do it again...he's not a common thief, he's a man who's just demonstrated that he's willing to take my life to get what he wants from me...and is able to immediately do so, and is likely to do so if I go after him to recover my property...and I would be legally and morally justified...
...the law does NOT say I will not be justified if he is running away...it specifically says "...to prevent the other who IS fleeing immediately after committing...aggravated(armed)robbery..." this law tells me that I have the right to prevent him if I choose...with deadly force...it does NOT tell me that I must sit there and watch an armed robber flee while doing nothing...
...in THIS OP's scenario...the law he quoted will justify his use of deadly force...walking through the law point and requirement by point and requirement...and disregarding our opinions...it does...and case after case has happened that way...
...is it illegal for you to choose NOT to use deadly force to stop him? no
...am I justified if I choose TO use deadly force to stop him...yes....by the letter of the law...point by point...
...the law pertaining to use of deadly force is written not only to restrain us from doing the illegal, but to give us the right way to excercise our rights...legally...we don't have to be lawyers to READ the law and see if we meet what it says or not...else the State of Texas would have us sign an affidavit that we had gone over and had explained to us by a lawyer what the law says about use of deadly force (
http://www.txdps.state.tx.us/internetfo ... CHL-86.pdf" onclick="window.open(this.href);return false; )...they wrote it so that WE can understand it and follow it...and it's expected that we understand it well enough to make decisions based on what it says point by point, not picking and choosing...it's not that hard...