Agreed. It never made sense for INO to premiere right in the middle of the Annie Arc, and David seems much more like his early (vs. later) season 5 self here.
After much pondering... and consideration of the many EU stories that densely pack the season 5 timeline... I have set INO at the only point where it can both logically and chronologically fit... shortly after SAS. I have also introduced the Available Concept "Judge, Jury, and Disillusioner", which explains that, at the time Agnes steps into Maddie's office to inform her bosses that she has been summoned for jury duty, David and Maddie are discussing an event from the previous weekend, as described in Marlena's story "Lovin' on Empty."
I tolerated the Agnes episodes and I never took to Viola, but after the awful ending to WGC, I wanted to see the next episode out of some kind of masochism, I suppose. But we got this instead - a filler episode that seemed to have been shoved in without any rhyme or reason. It still does.