Tha same cook had being cooking for settlement for a few years, he has 17 lvl cooking. But suddenly everyone got poisoned because of inexperienced cook. Really??? And it continues for a long time. What the hell?
i think that he either has health conditions (losing both eyes is a health condition), or you accidentally set to work an inexperienced cook.
i never had that problem with cooks beyond level 6-8
There is actually a very small chance it can happen even at level 20 skill!
For our automated accident-free kitchen (Project RimFactory) we had to directly patch the code to skip that chance :p So....you got unlucky. Maybe your cook got distracted that day and didn't realize they were grabbing day-old egg whites and ...ew?
Are you sure the meal was prepared by your skilled cook? I've had this happen when my pawns finally got around to eating year-old Stouffers dinners in the back of the freezer that had been originally prepared when they had low cooking skill or bought off of traders early game when food was scarce.