However, I don't care for your assumption that I did not "properly" read the entire phrase. I did, and I understand what was meant.
The citation of two instances in which similar constructs are used doesn't change my opinion. I can supply you with plenty of cases sloppy, imprecise, ungrammatical sentences or phrases that appear time-after-time in print. That does not legitimize them. How many times have you read or heard a news report saying "Several people were involved in the accident, but none were seriously injured"? Sounds ok, doesn't it?
The word 'single', when used as a numerical descriptor, has a pretty simple definition, which you can look up. It means "one". There is no such thing as 'one beneficiaries' -- there's one beneficiary or there are multiple beneficiaries. If a group is implied, it should be one "group", not one "groups".
In the interest of not wasting huge amounts of my time, I'll stop here. You can have the last word, and that's fine. If we disagree, that's fine, too. But I've learned that there's no point in spending half the day discussion English in discussion forums. (fora, if you prefer...)
I'm simply venturing an opinion, and I see your point. But that won't change my opinion, so I shall neither read nor respond to anything that you or anyone else may offer in either rebuttal or support. These things often veer off into the ditch of irrelevance through misinterpretation of previous comments and failed attempts at clarification.
Life's too short to spend arguing with strangers on the internet.