Graduation in/from/at

I read this sentence somewhere

After his graduation in the field of medicine at Harvard University, he was offered a great job.

Is this sentence grammatically correct? Aren't we supposed to use the preposition from instead of at and say:

After his graduation in the field of medicine from Harvard University, he was offered a great job

Yes, the second example is better. The difference becomes more striking if you omit the phrase "in the field of medicine": "His graduation at Harvard" might make sense only for the graduation ceremony, which could be said to occur "at" Harvard. Perhaps the author became distracted by the "field of medicine" phrase, which might have suggested "He studied medicine at Harvard."