In the last panel, is Youki or the author mistaken?

...or is it me?

DoubleT said:
In the last panel, is Youki or the author mistaken?

...or is it me?

I think it's Youki. The comic implies his memory is not good.

And in the second panel, there's a plot error by the author when he says Tenshi. Nobody in this room should know Tenshi ate the last mushroom yet.

Yukari said:
I thought they would certainly be blue colored medicines, but they aren’t.
Antidotes? So in other words, Cirno will not turn into a grown-up even if she eats them, right?

....That reminds me of a video I saw...Cirno swallowed a blue pill and turned into a grown-up...

_cf said:
And in the second panel, there's a plot error by the author when he says Tenshi. Nobody in this room should know Tenshi ate the last mushroom yet.

There was a phonecall (or walkietalkiecall) earlier, Marisa yelled something about Tenshi. They probably figured the rest out on their own.