I searched the wiki thoroughly, but I couldn't find any information about a specific Week 3 incident involving Kyle Pitts or any public criticism from Tommy Rees. The wiki covers Kyle Pitts' 2025 season (88 catches, 928 yards, 5 TDs), his 2026 outlook under new OC Tommy Rees and HC Kevin Stefanski, and even mentions his contract extension — but there's no report of a Week 3 outburst or a Rees criticism.
Here's what I do know from the Falcons page: heading into Week 3, both Michael Penix Jr. and Tua Tagovailoa were dealing with injuries, creating QB instability. Pitts was expected to be a focal point regardless, but there's nothing about a specific on-field mistake or coach criticism on record (from the Atlanta Falcons page).
It's possible this happened in a prior season (2025 or earlier), which is out of the wiki's scope (it only covers 2026+). If you have a specific source for the Rees criticism, I'm happy to search for it with fresh terms.