To me it implies criticism and ridicule,
Hergé was setting out to make fun of them, and said so in an interview; when he talked to Numa Sadoul, Sadoul asked him about the incident. From p.183 of Tintin et Moi, Entretiens avec Hergé
Sadould: Ses rédacteurs ne vous en ont pas voulu?
Hergé: Je ne crois pas. Je crois même savoir qu'ils en ont bien ri. Ils ont le sens de l'humour, à Paris... euh, Flash!
Je pensais évidemment à un célèbre hebdomadaire coutumier de l'erreur, au point de croire qu'il y avait, au sein de la rédaction, un membre spécialement payé pour introduire des fautes!
Which roughly translates as:
Sadoul: Its editors didn't hold it against you?
Hergé: I don't think so. I even believe that they had a good laugh about it. They have a sense of humor in Paris... err, Flash!
Obviously, I was thinking of a famous weekly that was accustomed to errors, to the point of believing that there was, within their editorial staff, a member especially paid to introduce mistakes!
He related an incident where he'd been interviewed by journalists about Tintin
, and they had (for some reason) got him to provide the accurate dimensions of the Tintin & Snowy sign on top of the Le Lombard building in Brussels, which he got for them for their notes - and when the article came out, they had garbled the stats so that, "everything was changed, inverted: 25m had become 2m50, 3m50 had become 35m...! So I played at putting a bunch of disconnections in the same style in my story, and I had a lot of fun doing it