More that he distrusted calculation prepared and designed by anyone other than one of the main characters.
The part where computers aren't magic and won't magically come up with correct answers despite bad input (calculation formulas in this case) was already a well established thing.
EDIT: As for well-knowness of computers - it was early enough in history of computing that Digital Equipment Corporation, despite starting with pretty much a blueprint for good computer, had to carefully ensure that it's first commercial computer didn't call itself a computer. Thus PDP series was born.
