Unsure if the fly was succumbing to Puppeteer Fungus. It's movements were very sluggish and whilst it eventually flew away, the images show what appear to be white spores over the body and on the underside of the wings, similar to fungus spore outbreaks seen on other flies. There also appears to be some outbreak of white material along the underside of the body however, I'm not familiar with this type of fly and it may just be body markings.