Didn't Bob De Moor write some short Tintin stories running to one or two pages?
Yes - we've discussed at least one of them in the past: Les Gorilles de la Vedette
("Bodyguards to the Stars") was written as a little tribute to Hergé at the time of the unveiling of the statue of Tintin in Uccle.
did Moulinsart turn a blind eye to these short creations? Or were they unofficial pastiches?
They are not "official" in that they don't make up part of the canon, nor were they intended to to. However, Tintin
magazine might as well have been the house magazine for the Studios in those days, so they had far more leeway to render jokes of this kind than anyone else would ever have.
Look on it as the work of a beloved employee playing a practical joke on a benevolent boss - the fact that it was done by someone who knew him, for a publication which was authorized by him, to mark a special occasion, doesn't mean that anyone else at any other time could do the same thing...
You also have to bear in mind that the final decision to stop creating new Tintin was not an instant one: it was thought at first that the work might continue on Alph-Art
, and the studio staff were involved in commercial projects which had been undertaken while Hergé was alive. Producing the odd little cartoon for the journal might have been thought to be something to placate the readers, as well as carrying on the traditions of characters being combined for one off humorous pieces or appearing in little skits while Hergé had been alive. It was only when Mme Rodwell was presented with the paperwork for completion and publication of Alph-Art
that consolidated her resolve to carry out Hergé's wish for Tintin to end with his death. This and the end of the magazine brought such outings to an end.