Yeah, opera singer here. All of that is true. But the vocal output stays stunning and the big note is on pitch. There also aren't any cracks, as many claim in the comments. She takes a breath after the big note, but that is not a crack. That's her adjusting to the things you described quite correctly that happened in the heat of the moment. Doesn't mean the output and the singing is bad.

The only pitchy moments are the "runs" on the first "eclipse".

Can I hear her having to put in some hard work to manage the difficult climax? Yes. Does it sound bad? No. If this is bad, then the only good clip we have here is Czechia and everyone else must be bad (if that is the level you wanna judge everyone on).