Which Rider Is Cancellng?

I've just read about the Rider trip cancel scam for the first time.

I often see 'Rider Cancelled' and had never thought about it, as I've always assumed it's the next queued Rider cancelling because they don't like the surge or changed their mind. It never occurred to me that it might be the current Rider trying it on. My question is this: how do I know which Rider is cancelling - the current or prospective one?