I don’t know why you think this makes the situations fundamentally different. Either way, either a legally enforceable situation has or has not been created. I don’t see why you consider that whether the sender or recipient is the one wishing to enforce make the two situations relevantly different.
Oh. Would it? Great. Because I’ve been practicing in this field for 25 years and at least in my jurisdiction I’ve had to give far more nuanced and less certain advice on this topic. But it’s great that I now have The Answer.
Or to put it another way, perhaps in GQ you shouldn’t offer opinions as fact, the more so since unless I fail to recall correctly, you don’t have legal qualifications.