Thank you for engaging my point. I will say, you are not bad. In fact you are reasonable- as some others wanted to exclusively focus on that. Few other posters and I even commented you were too reasonable. Please take this as free feedback from people who can both see your oversight and that the bloke is a right pain.
Thank you for identifying where you went totally wrong - not documenting everything. However, I have seen worse mistakes than that.
The good thing is that, even as your conversations with him were not properly focused on the issue (data production- perhaps because you failed to spot what the issue was causing him delays) but only on 'giving extensions' (you still don't say you would have recognised that he was doing a wrong task had you taken 15 mins to just have a quick glance); instead of also not checking the task was on teh right track. Or are you new in your field/ role that you couldn't have spotted a presentation from 'data' a mile off? If so, you need to work on your hard skills too.
Managing people is not easy. It is why, I refused a big promotion and lots of money, within 3 years of experience and I could do the job, because I was determined I wanted to continue picking up more skills in another specific practice area, in addition to that I was expert in, so I would be self-employed at a later stage as I too disliked being employed, but rather wanted to focus on delivering on actual issues.
I am a lawyer. That means, keeping accurate records of all interactions is part of my day job. So we get to learn to do it, in 5 mins. I can however confidently say keeping records is part and parcel of managing others. In a situation like this, you ought to also share your notes (or one of them) in an email to the bloke so he can comment if he doesn't agree. I am sure there was a stage where you lost confidence in what he was doing, hence you decided to just get on with your preparation of the presentation without his data. AT this point, a bit more was required from you, instead of a shrug or annoyance and 'getting on with it.'
I have some good news for you though, why I took the time to write fully. HR are unlikely to come back to you, mainly because you have evidence that you spoke to the bloke many times. That is enough (at least for now). But your line manager, should be sending this post I have just made for you. There is no reason why you should not be believed. I hope though, that you didn't follow the earlier advice of quick points in your reply, (you had not sufficiently said you spoke many times), as that is what HR need to hear about. And if they do come back to you, it will be for more content of those conversations.
Hard lesson, but I feel you have/ will learn(t) from it. Don't overlook hard skills, if you need to address that too- your line manager should be able to point that out to you, if perhaps you cannot see it and it contributed to this oversight. HR might take a different approach to a similar complaint from same bloke about you, so watch out.