Yeah, this is how it goes. They don't run tests, they just accept what a player says. FYI for something like an ankle injury they will have ran scans to get a look at his ankle, and if there were any signs he still had issues, they won't clear him.
You will be cleared by medical staff to train. The coaches will then assess you in training and it's up to them to decide if you're really match fit. If Kane didn't look match fit, he shouldn't have been picked.
That's the last I'll say on it, it's really bizarre people are feeling the need to have a pop at Kane for either wanting to play a final, or now inventing that he lied to people. Find real reasons to criticise him, you have plenty.