Leon who stood in front of Dan remembered Richter's past assessment of the man. Richter said Dan's combat skills were better than his own, but only in close-quarters combat. The only reason Richter was able to defeat Dan so easily last time, was because for some reason Dan was already injured, and he was able to catch Dan by surprise. Now that the man claims to be stronger than before, Leon couldn't follow Richter's rules, he needed to fight without any more restrictions.
Leon sped up and got near Kei and Evangeline. Dan who saw this reacted fast enough and blocked Leon's way, unfortunately for him Leon wasn't really aiming for the kids, but their weapons. Leon took Kei's rifle and Evangeline's pistols.
When Dan saw Leon holding those guns he felt a chill down his spine, it would seem Leon was even more dangerous when he uses such weapons.
