Lucien Enjolras

"I imagine so." More ways than the potential crush which Claudius could claim was a mistake on his part -- but that's not the picture he's getting. Grantaire came into the mansion covered in his own blood and the blood of his fellows after dying in a revolution he spoke very cynically about. Something or someone must have inspired him to put his life down for it, and Claudius assumed it was his esteem for his friends¹. "Which is the most surprising?"

¹ On reflection, Claudius's half-acknowledged plan to throw himself at a young man who doesn't care about causes had a flaw. 'Dying to be with someone you deeply care about' sounds suspiciously like a cause.