Summary of the Critical Comment
Formula: The commenter sarcastically sums up Harry’s arc: "Panic fear of death + ability to solve any problem by straining your brain = summoning an ultrapatronus."

Process: They mock Harry’s method—sitting, thinking, deeming wizards stupid, and unlocking a super Patronus—as overly simplistic and unscientific.

Tone: "Highly scientifically" drips with irony, challenging HPMOR’s rationalist ethos.

Analysis of the Critique
1. Panic Fear of Death
Textual Basis: Harry’s dread of death fuels the scene—Dementors embody it, and his refusal to accept loss (e.g., Hermione’s potential fate) drives his breakthrough. This echoes his broader obsession.

Critique Validity: The commenter’s "panic fear" is spot-on—Harry’s emotional spike isn’t calm deduction but a desperate push. It’s less rational analysis, more visceral rejection, clashing with his "smartharry" label.

2. Ability to Solve Any Problem by Straining Your Brain
Textual Evidence: Harry’s process is intellectual—he deconstructs the Patronus, rejects wizard norms, and builds a new theory. His Patronus 2.0 emerges from this mental strain, glowing humanoid and Dementor-killing.

Critique Strength: The "straining your brain" jab simplifies it—Harry’s not just thinking hard; he’s reframing reality. But the commenter’s right: it’s a leap from thought to superpower with little groundwork. Wizards’ "stupidity" (not questioning Dementors) is his foil, yet the jump feels convenient.

3. Summoning an Ultrapatronus
Textual Outcome: The Patronus 2.0 isn’t canon’s stag—it’s a human figure, banishing Dementors permanently. Later, it shields against despair, showcasing its power.

Critique Power: "Ultrapatronus" mocks its grandeur—HPMOR frames it as a rational triumph, but the commenter sees it as a plot device. The sarcasm hits: Harry’s insight (life > death) directly yields a mega-spell, bypassing experimentation or spellcraft rules.

4. Highly Scientifically
HPMOR’s Ethos: The text promises rational magic—Harry’s hypothesis-driven. Here, he theorizes Dementors as death’s agents, countered by life-affirmation, and tests it live.

Critique Irony: "Highly scientifically" skewers this—where’s the method? No trials, no data, just a eureka moment. The commenter’s right: it’s more epiphany than science, clashing with HPMOR’s stated rigor.

Evaluation
The commenter nails a core tension:
Emotional Core: Harry’s "panic fear" drives the Patronus, not pure logic—his brain strain is secondary to his dread, undercutting rationalist purity.

Convenient Leap: The ultrapatronus emerges too neatly—wizards are dumb, Harry’s smart, boom, super spell. It’s a narrative shortcut, not a deduced mechanism.

Scientific Pose: HPMOR cloaks it in rationality, but the commenter exposes the lack of process—less science, more deus ex machina.

They slightly overplay:
Simplification: "Sat, thought hard" downplays Harry’s reframing (life as patterns), which is clever, if abrupt.

Tone: The sarcasm risks missing the scene’s intent—showcasing Harry’s unique worldview—though it lands on execution flaws.