Thanks to Peter Mühlhäusler, I’ve got hold of a copy of a 1955 report by W.C. Groves, then the Director of Education in the Territory of Papua and New Guinea. The title is The Problem of Language: Paper no 1: “Pidgin”. Here are some quotations from the summary of the report (pages i- ii):

Pidgin is a language in its own right... Practically any concept that can be expressed in English can in fact be expressed fully and without ambiguity in Pidgin...
As to Education, experience has shown that Pidgin is not only a useful, but also an adequate means of instruction in most fields...
The use of Pidgin for formal instruction in organized teaching institutions enables instruction to be given through that medium immediately, since the language is known to the students as a starting point. To wait upon the Natives’ learning of English would be to deny them literacy and a wide range of educational interests for years and years and thus to retard the development of the people...
I believe that, if Pidgin were officially and openly adapted for educational and other communication purposes in the Territory...the result in accelerated development of the Native people would be inestimable.