Except the way the Texas law is worded, the jury is not allowed to consider whether he could have retreated in determining whether his actions were reasonable IF he qualified for the SYG protection.
The jury must find that he was in a place he had a legal right to be (i.e. not on Danaher's property) and that he did not provoke the confrontation. If Rodriguez cannot show those two elements to the jury, then the jury can consider whether or not a reasonable person would have retreated in that circumstance - and if the jury gets that far, I am pretty sure Rodriguez is going to prison.
Although I suppose that based on the testimony the jury could conclude that Rodriguez went there looking for an excuse to use his gun and could find his fear unreasonable without considering the retreat issue, though I think that would be a tough needle to thread.
More testimony from yesterday reported by the Chronicle:
http://www.chron.com/news/houston-te...of-3626044.php
Rodriguez's neighbor Pete Fornols testified that the day prior to the shooting, Rodriguez had used some foul language to describe Mr. Danaher, so apparently there is some pre-existing anger there, at least on his side. Fornols also testified that Rodriguez called him 13 times that night trying to get him to help complain about the music.