You mean the fact checkers could be wrong?

“I have now asked the intelligence community to redouble their efforts to collect and analyze information that could bring us closer to a definitive conclusion, and to report back to me in 90 days,” Mr. Biden said. “As part of that report, I have asked for areas of further inquiry that may be required, including specific questions for China.”

If the intelligence community wasn’t doing this sooner it can only be that they were assured it was impossible by the fact-checkers.