Just got out of a game as PB where I infected everyone but did not turn into pest.
In N3 I infected the jugg and when day 4 started he and I were the remaining two. He was infected but I did not become Pest. I thought I might when the night started but when the next night did start I remained as PB and did not transform into pest.
https://i.imgur.com/f2ry5fp.png
In the image, you can see the night started with me and the jugg and the jugg is infected but I never became pest.
Incidentally, this is not the first time this happened to me. In a previous game long ago I infected everyone by n4 but the pest transformation never happened.