Now, I can see some arguments about ambiguity in the first sentence about timing, but that's at the level of a tweet, not errata.
It's not so ambiguous if we apply some syntactical parsing. It's not a compound sentence but it is a complex sentence, so there are multiple clauses with regard to the subject (you, or specifically familiar here) and the predicate (aid). The clauses in our sentence are "aid a friendly creature in attacking a creature" and "aid within 5 feet of you."
Since there is no clause or further clarification that you have to be in some sort of Help State or Help Concentration at the time of the attack, the Help Action is an at-will action. The following sentence clarifies that aid is rendered against the target creature.
Given all that, we have a sentence that says: You aid a friendly creature in attacking a target (fun fact, target can be friendly to you), and you aid while the target is within 5 feet at the time the Help Action is taken. The requirement for Help to benefit the attacker is simply the attack occurs before your next turn.
Things you learn writing a natural language parser.
You can, of course, read it different ways, such as the argument "aid [...] attacking a creature within 5 feet of you." That requires introducing new implied information to the sentence (rearranging syntactic atoms, additional punctuation, new subordinate clauses, etc).
The narrative believability is the least of the problems. As a narrative, there are virtually limitless options that explain how you did some sort of distraction, you and/or the target moved, and the attack was made.