The experts' anger was not an act, as they really did not want to mess with Andrew and his collaborators. They had already done their homework and while they did not know the extent of Andrew's power, what they knew was more than enough to fear.
Shadow's agent had a proud smile under his mask, as he knew he had accomplished something great. He knew that Castor, who was in charge of everything in Andrew and Oliver's absence, was eager to get revenge on Spigas and it seemed that he would succeed.
Just as Shadow's agent had thought, the experts immediately began to ask how they could correct the mistake, "What can we do to not be included with that fat fool?"
As had been said, the experts are the most afraid of losing their lives. It is true that they do dangerous jobs that generally involve battles that can cost them their lives, but if they can avoid them, they would be glad to do it.