Our schizo boi here did all possible tests and even he couldnt identify the poison/curse used.
Also note that this is the kinda school where children of military generals and prime ministers eat communally at the canteen. Poisoning isnt a big worry for this safe school environment.
Lastly, she's not exactly unverified. To an outsider, she is a noble who stands to lose all wealth and titles if she poisons royalty.
Or this is just the author using stupid otome game tropes as an excuse to reduce his workload lmao
The cookies given to the prince were already poison tested (probably by someone else eating them) and it had no effect presumably. A pre-clinical test using mice (which is essentially what Rufus did) isn't really a common procedure. In regards to the results of the poison testing, it's mentioned that the cookies only affect people when they're given frequently (once every 5 days already has a slight effect on the mice), and in Rufus' test the pieces of cookies that are given to the mice are as big as them, so you should expect the effect on humans to be less severe, so to the poison tester, who I presume only ate it once, should not have been affected that much, at least not enough to warrant suspicion on the cookies.that's what I mean!
You would think a royal family of all would employ all sorts of tests to figure out any possible drugs/poisons, if not straight up having a policy to reject any and all foods from non verified sources!
If our boi here can do the mouse test, by all means they should have done so too!