It's a bit of time I'm asking myself this question.
Let's imagine the following situation:
A guy visits another guy to receive a payment in BTC.
He doesn't have a mobile internet connection, so he asks his host to connect to his host's wi-fi.
His host, that we assume for the sake of our inquiry wants to scam his guest, connects him to a fake internet in which the real BTC blockchain was forked in order to fake a transaction that in really will never happen.
So once the first guy will go back home he'll see that his payment has disappeared.
Is this situation technically possible?
I this it is possible to do but the guy will notice it eventually of course and you just make it appear that he has received the transaction or make it appear like a legit transaction in the blockchain but not really a hack or sending a fake bitcoin, I think your going to need to crack the code of the bitcoin to fake a transaction but the method you just says is just making it appear a transaction was made but it was not. By the way transaction in the blockchain could sometimes cancel it happened to be sometimes due to traffic.