Semester Project

In my developmental biology class we had a semester project. An intense semester project. We had to come up with a question related to human development, propose a hypothesis and an experiment, and state what we thought the results would be. It was supposed to be something that had not been done before. It's a 400 level class. And it was way intimidating. We were in groups of four. But through some strange turn of events one of my group members dropped the class and the other stopped coming to class and our project meetings. So my professor told my one remaining group member and myself, with a week and a half until the due date, to press forward just the two of us, even if the third guy was emailing about what he should do.
He gave us an extra week to turn in the project. He allowed us to do the simplest experiment proposal ever (not a joke-- if I could understand it it was very simple). And the day before it was due he told us not to worry about our grade because he was going to go a bit easier on us because of the strange circumstance.
In the syllabus and some extra course documents he mentions that it is almost impossible to get an A on the semester project. I just checked the grades. My group got a 100%. I feel like I didn't deserve this grade. And that makes me feel like crap. And I worked hard. I read lots of papers, I spent lots of time on group meetings, I had several revisions, I pushed the two of us to do well. Do I think we deserved a good grade? Yes. Do I think he should have been a bit easier on us? Given the circumstances, yes, but given the extended deadline, not really. Do I think we deserved 100%? Definitely not.