Any possibility that... (SPOILERS)

Any possibility that Alvin Straight was the person who was watching Rose's kids the night there was a fire, resulting in her son being burnt, and her children being taken away from her? A few things lead me to believe that this could have happened, or is possibly hinted at. Alvin also tells about his friend in the war that he inadvertently shot, when everybody else believed that it was a Nazi sniper who had shot him. He said that nobody except him ever knew the truth. This could be a subtle way of telling the audience that Alvin could have allowed the same thing to happen with Rose. Perhaps he had started the fire (maybe a connection to his drinking?), and was too ashamed to admit it was his fault, and allowed the kids to be taken away from his daughter. Is it possible that Lyle knew the truth, which caused the tension between the two of them, and why he didn't want Rose to come with?

I could be completely wrong, but I couldn't help think this (and was actually expecting this to come up when Alvin and Lyle met up at the end).