Considering the importance of the topic, and provided the linked articles actually contained examples of Google censoring anti-war propaganda, I believe the swipe would have been fully justified.

Highly emotional tone changes how the data affects the reader. If he is right, I would surely better remember next time that Google is in the same ballpark due to the insult hitting hard. If he is wrong, I will know better to ignore such claims in the future without a direct quote or something else that consumes less time than reading an entire linked article.