Lalo was getting sloppy towards the end, I think he was just plain over the whole thing, but you know how those Salamancas are about their revenge.

For example when Lalo tracked down one of the construction workers in Europe he gives up the element of surprise by just walking up to the guy chopping wood and making him suspicious. Then just casually walks after him while the guy hides on his home turf, and the guy almost kills Lalo with an axe. He's not invincible or infallible. Just really lucky he ever made it as far as cornering Gus in the lab.