Is what happened considered accidental killing that necessitates compensation, and who is responsible for it, the supervising physician or the resident physician, especially since the resident physician strongly believes he consulted the supervising physician, and does the resident physician bear the responsibility alone?

The fundamental principle is the acquittal of liabilities from rights until that which necessitates the establishment of a right becomes clear. Therefore, doubt concerning the causation of a patient's death does not entail any consequence, nor does it necessitate expiation or blood money. Funds are sacrosanct except with certainty. A physician is responsible for his error in specific circumstances. If a trustworthy scholar issues a fatwa (definition) to you stating no liability, then you are permitted to act upon his fatwa.