So if I tell you it was bad to be late (it was bad) then you will feel guilty it was late.
If I tell you it was OK to be late then you will feel bad that this did not work out because you weren't qualified.
So what I will say is that it sounds like in this situation it was probably both. Your impression with a potential employer is the sum total or your timeliness, correct spelling and grammar on your resume and application and any other paperwork along with your results on the interview.
Many employers will give you the impression on an interview that you are going to get a call back soon or that you are IN but they need to go through the formalities, etc. I had one employer take me around and introduce me to others I would be working with. Later I met another applicant they did this same thing with.
This is just an easier way for them to end things on a positive note with you.
Also at that point in the process you may have been the choice candidate and later lost out to the last person they interviewed.
20 years retail management, 11 years IT Systems Engineer, Tech author, Tech editor