Answer:
Hasty generalization fallacy
Explanation:
Fallacy can be said to be a reasoning which leads to the wrong interpretation of a statement or an argument. Although some people intentionally make fallacious statements just to score cheap points or to please the listening audience, but some make fallacious unknowingly, either due to carelessness or by being lackadaisical.
In this case the writer, without enough investigation and proof, comes to a very hasty conclusion that "all doctors are the same". This is termed a hasty conclusion because the writer only had dealings with just two docotors(Dr. Ames and Dr. Collins). So saying all doctors are the same just because of two instance is a rather rash statement.
Therefore, the fallacy commited by the writer here is a fallacy of hasty generalization.
Hasty generalization fallacy occurs when someone has a limited information on a population but makes a conclusion based on a larger population than he/she should.