Either I have missed something or the author of this article needs to go back to journalism school. The article seems to be saying this Bishop officiated at the funeral Mass of the accused priest. “Concelebrating” a Mass refers to two or more priests presiding over the Mass together. Therefore, unless Accused Priest got out of his casket like Lazarus and co-presided over his own funeral Mass, there was no “concelebrating” going on here.
The first paragraph that says the Bishop celebrated Mass “alongside” the Accused Priest could be correct, I guess, if you consider that the funeral was likely taking place “alongside” the corpse in its casket, but it too is misleading in that it suggests the Bishop and this priest said a Mass together.