My take is that this was not a plan loan at all, or I'll temper that a bit and say it may not be. Insurance, in my opinion, should be considered just another asset of the plan, with some unique characteristics. One of them is that if the plan is otherwise pooled, any insurance is effectively self-directed/segregated. That may or may not be relevant but the point is that premiums, loans or other transactions involving the insurance "account" should be considered transfers between accounts.
So you have money coming out of the insurance policy and going to a participant. The "coming out" part is a transfer out of the policy, and (to my way of thinking) you first have an effective transfer to a "side fund" (old admin terminology for everything not insurance) and then...ah, here is the question. It's either a loan, or a distribution. Of course there was no paperwork either way, and the consequences (ultimately) are the same - taxable income. How to treat it might depend on whether loans were permitted, what shred of paperwork might exist, etc. What you do have is an unfortunate mess, probably created by the agent in setting up the policy ownership correctly, and the insurance company, for being sloppy and letting it happen and then allowing the loan. None of which is surprising.
(I may be complicating the situation by creating a phantom step but I don't feel like re-typing. I guess you could boil it down to either a loan or a distribution, directly from the policy. But adding the intermediate step helps, I think, to prevent the line of thought that there could or should be direct dealings with the insurance company and participants.)