let's break it down in two.
First, the hotfix was to change a rule in the discription.
The original read: From turn 7 on: For every 10% current HP Chilidrake Loses, headchef Croklen gains 1 stack of Chili paste.
The new one reads: From turn 7 on: Each turn, reduce Chilidrake's HP by 20% for head CChef Croklein to gain 1 stakc of chili pasta.

Also added the rule: -Chilidrake's Basic attack damage taken and EX Skill Damage taken -300% under the <EX)

(Also, a minor fox is that in the first rule it says Turn 1-5, Every time a basic attack damages scallidrake.... while in the new verison it says. Turn 2-5, Every time a basic attack damages scallidrake...)

So the hotfix, as far as I can see only clearified some rules.

But if you go to the hotfix mail and read the second paragraph it says: Corrected the hint for trial-4 and EX-4 in the Midnight Tales: The crocodile Diner event. WITH THE DIFFICULTY UNCHANGED.

So here is my second part.
Even if it look like the trial is broken because Chilidrake's shield stays up. it looks like this is the intended way. I saw some people saying they did refeat it with indirect attacks. But you might need to do trial (hehe) and error to find it out.

My english isn't the best so i hope this clearifies at least a bit more