I would also have thought that this might fall under the category of a donor paying and expense for which the organization would otherwise have been liable.
But when a donor directly pays, as you say, a premium for a life insurance policy owned by the organization, there is no expectation that the life insurance company would have been authorized to receive gifts on behalf of the organization. They just accept a payment in the usual manner for an obligation for which the organization would otherwise be liable.
The point about the need for documentation of the payment to be able to determine the actual donor is well-taken, of course.
My US$0.02 worth; the usual disclaimers apply.
Alan S. Hejnal (he/him/his)
Data Quality Manager