Harkam didn't find that suspicious at all. The only thing on his mind right now is that they will be wasting their one chance to use the annihilator. It wouldn't help the strike team which means Tanya might die. That's why he is complaining moments after complimenting the "dwarf sun god."
Complain as he might, no one listened to him. The annihilator was fired and it went to waste. The ant horde was disoriented but the damage done to them was minimal. The royal guards weren't where they should and most of the ant horde was at the front lines or concentrating on the strike team.