Except that Ong's work is also based on observations made by people.
Hand up, here, I've not read the work myself, but from the reviews I've read the general commentary is that his work is predominantly theoretical. No-one went so far in the reviews to accuse him of cherry picking any practical work, but they were fairly consistent in saying that the prevailing practical research went against his conclusions.
Regarding his formal status, does that make any difference? After all, Mendel ('father of genetics') was a monk.
An argument stands on its own merits, and I hope I've put forward why I think the argument doesn't stand up. My noting that he was a Jesuit priest - a group who, in general, have a good track record for academic work - was more an attempt to understand why he might cleave to a path that the evidence based thinking of the time (this was the early 80s when he published) didn't support.
Coupled with the fact that the bulk of his actual scholarly work wasn't to do with the veracity or consistency of the oral traditions, but rather the impact literacy had on culture - it was, therefore, focussed more on the cultures that WERE literate than those that weren't - it suggests that he's not an ideal prop for the argument of oral inerrancy.
For your information, I first heard about Ong as part of my MA in Applied Linguistics and TESOL from the University of Leicester.
My background is science, computing and engineering, however the argument stands on its merits, not on the Reverend's calling or education, nor on yours or mine.
O.