A shot is not a shot unless it is a vague aim at goal though....lol. I get where you're coming from and it is a bit of a grey area perhaps but the likelihood of actually scoring doesn't make it any less aimed or even the difficulty in execution. Of course he isn't aiming with precision, he's vaguely aiming at goal no?
The fact he has tried this kind of thing many times with no success in training suggests that his action in actually scoring was a trained and honed instinct and an action in which he is aiming to score.
If he was executing a pass back to Petr Cech, he wouldn't then stand there with his hands on his hips thinking, I really hope this ends up in the back of the opposition keeper's net... because it would be virtually impossible and he hasn't actually taken a 'shot'. He hit the ball with his goal and hoped it went it because he was vaguely directing it towards goal instinctively. The fact it was instinctive also doesn't mean it wasn't a purposeful action.
I have absolutely no problem with anybody who thinks hit was hugely fortuitous but I don't think you can completely remove the element of intention from the goal either.