I personally do not find this objectionable at all. Of course, it is not a very impressive kill, as killing someone by surprising them is not in the same league as killing someone fully prepared.
However, I heartily approve of any actions that demonstrate a lack of safety, and forces people to be more alert and attentive, wherever they happen to be. A good shipping or two can be a marvellous cure for complacancy.
Written by my hand on the 27th of Mournsend, in the year 1042.