Most druids in Skellige differ from the deeply-rooted Continental stereotype of a graybearded old man in white robes bowing before sacred oaks, taming wyverns and pestering local lords with petitions to add yet another species to the list of protected beasts. Ermion, Geralt's old acquaintance, was no exception in this regard.
This stiff-bearded, spindly man was the leader of the Druids' Circle in Skellige. He was also Jarl Crach an Craites advisor on matters of magic and the mystical, as well as on any and all issues requiring more refinement thana well-timed uppercut ora hard-swung axe.
Ermion was known to be obstinate and to have a tendency, quite rare in Skellige, to consider all possible consequences of a particular course of action before it was undertaken. All this meant that conversing with him demanded a considerable amount of time and patience.
Given all this, one can hardly be surprised that Yennefer and Geralt's "rash" and "highly irresponsible" actions regarding the magic anomaly-stealing a priceless artifact from a private chamber being first among them - put Ermion quite out of sorts.