Unfortunately, Thompson isn't of much use to him anymore. What is left of Thompson is their childhood friendship.
So he only felt that Thompson would be missed and that it was a pity that he died so young. He didn't feel more than that at all.
Despite the shallow impact of Thompson's death on him, he is probably the only one on this ship, apart from his students and Geltra, who feels something about his death.
He is sure that Lady Delie and his mother don't feel anything about Thompson's death. If Lady Vena, of all people, who knew Thompson didn't feel much and used Thompson's death as a teaching opportunity for her son, then no one else in the Dyson family will care that the son of her servant died in the exam.
He thought to himself darkly as he glanced at Geltra and Lady Vena, "I wonder what Mother will feel if Geltra dies."
He chuckled inwardly after thinking that.