The article says the culprit is a virus and a fungus. What are you saying?
He's claiming that the findings are susepct because the principal investigator allegedly recieved a grant from Bayer, a pharmaceutical company that also happens to manufacture pestisides.
You see, many people suspect that it is pesticides that are killing the bees, and apparently bee keepers have been suing pesticide makers over the deaths of their hives. The research cited in the article doesn't help their case, and so they are trying to discredit the scientist by bringing up his Bayer grant.
Of course, the mere fact that this guy took a grant from Bayer doesn't mean his findings are wrong. As others have already pointed out, scientific research stands or falls on its own merits. Just because the guy took a Bayer grant doesn't mean his findings are wrong. Perhaps it means those findings should be vetted more carefully, but at the end of the day, the question of whether the guy took a grant from Bayer doesn't matter.