Raziel was on his horse, surrounded by and fighting against more than ten enemies at a time. He seemed to be their target.
He needed absolute focus in fighting them all, thereby distracting him from observing his surroundings. Luckily for him, he was swift with the sword, and thanks to Luciana's poison, every slash sent the soldiers falling. He always aimed for the part that would kill them at a strike.
While he was distracted, he didn't notice Elric targeting him with his pistol. And Lorenzo and the others were also kept busy, so no one noticed. Plus the duke was perfect with his aiming.
When the first bullet hit Raziel's arm, he turned to the source of it, but he got distracted again by the swarms of soldiers fighting him off.
Then another hit one of one of his calves. The shooter was trying to weaken him.
Raziel knew that he needed to get those bullets out of his body, so that he could heal, but he was not given the chance.