It was unlike Hugh to be interested in a stranger's opinion of wine.

It was unlike him to drink wine which was evidently not to his taste.

And it was especially unlike his customary courtesy to let himself fall into thought at dinner-time, when there were other persons at the table.

Was he ill?
Impossible to look at him, and not see that he was in perfect health.

What did it mean?
Finding Mountjoy inattentive, Mr.Vimpany addressed himself to Iris.
"I had to ride hard, Miss Henley, to get home in time for dinner.