This is CNN debunking the claim that people with Covid, 85% wore masks, but also proving it.

The study also found that, of the 154 participants who tested positive, a total of 85% said they had worn a mask either "always" (70.6%) or "often" (14.4%) over the 14 days prior to the onset of their illness. Of the 160 people who had tested negative, conversely, a total of 88.7% said they had worn a mask either "always" (74.2%) or "often" (14.5%).