Especially after those giant spiders got dragged into this wizarding war, Hagrid had to make a choice between Aragog's descendants and his own colleagues.
It was undoubtedly a painful and difficult choice, but Albert's repeated efforts finally made Hagrid realize he had to make up his mind: stand with Harry and everyone else, instead of acting stupid just because this pack of Acromantulas were Aragog's descendants.
"We need to help everyone deal with Aragog's descendants so that others can spare hands to help fight those Dark wizards invading the Castle." Hagrid looked downcast, but he didn't forget Albert's instructions. He pulled out a piece of parchment from his pocket, read through it again, and said to Firenze beside him, "This is the mission assigned to us."
Chapter 1357