As you've demonstrated, there was no need for self-reference as there is other material in the field. That the author would first go to self-reference remains a red flag to me.

I encountered this years ago on the Dunning Kruger Effect. For two decades almost everything in the field was written, or collaborated on by one or the other or both. As you know, the gold standard is replication of results. For decades no one was ever able to replicate the results, until a team loaded random data into the model. THAT duplicated the results.