People are not accusing Hunter Biden of somehow breaking Ukranian law during his time "at" Burisma. They are saying that Burisma was being investigated for a potential crime, and then hired Hunter onto their board, and then Joe Biden got the prosecutor looking into Burisma fired.
IN fact the article linked under the words "walking back" in the above paragraph is a Bloomberg piece which lays out that precise timeline, despite pretending that that somehow exonerates the Bidens from the accusation of conflict of interest.
https://www.bloomberg.com/news/articles/2019-05-16/ukraine-prosecutor-says-no-evidence-of-wrongdoing-by-bidens
Journalism in the country is dead, except for John Solomon.