Is what happened considered attempted murder or accidental death if the mechanic was harmed and died because he was not warned to wear protective gear when touching the car tires that passed through an unknown puddle?

Anxiety and doubts about harming others due to a car driving over water are merely baseless satanic whisperings. The original principle is that street mud and water are pure unless their impurity is known, and a car often removes any filth clinging to it. Such matters are apparent to a person in the profession, who is more knowledgeable about what requires precaution. It is obligatory to occupy oneself with what is beneficial and to ward off these whisperings and delusions from the self. The Prophet, peace and blessings be upon him, used to seek refuge from worry and grief, because they bring no benefit and repel no harm, and they may lead to a weakening of the heart and preoccupation with them from what Allah has commanded.