It sounds like he published some theoretical musings back in 1990s without any real practical implementation that did anything useful and since then has run around accusing AI researchers who actually produced concrete research and techniques to get are actually in use today of plagiarism.
On the other hand, if his claims are verified, some of these research “discoveries” are simply common sense and would occur to most people working on the subject. HLB were awarded to a good extent because they worked on deep learning at the right time. Deep learning became hugely practical, and outperformed the state of the art in many applications. HL also worked for major companies.
He published working models back then, the problem was compute power was very limited. In the past decade deep learning took off, people took his models, renamed then and ran them on vastly more powerful computers, to great success, then failed to cite him.
Don't you know that billions of people are using his work on a daily basis on their smartphone? CV: https://people.idsia.ch/~juergen/cv.html