Sloppy math

In response to a glaring error in one sentence of this op-ed, I sent the following letter to the Los Angeles Times (not published):

Teicholz says, "The claims ... have been shown ... to be correct only 0% to 20% of the time." 

Fine. But she then says, "This means that 80% to 100% of the time, they're wrong."

That's completely wrong. It means they might be wrong, but they might be right, too. We can't know.