Got dumped: Honest reason or lame excuse?

Hey guys! I'm super curious of other people's POV of this situation.

Background, I first met this person about 7 months or so ago. He was a great guy who I was interested in, however I'm a very laid back person and wasn't going to push a relationship on a guy.

We started casually going out, and he quickly asked me to become exclusive after a month or so....which took me by surprise, but I agreed. Nothing about our relationship dynamic changed- we saw each other maybe once a week and possibly texted/talked on the phone every few days. Whenever we were together he liked to bring up how his family and friends were happy he was finally seeing someone after apparently getting out of a nasty relationship a year or two prior.

Soon after dating he got a job promotion and became incredibly busy and anxious about work. Without dragging out details, he very recently broke up with me saying he didn't have enough time to devote to a relationship, and how letting me down on not being able to follow up with plans was making him anxious. Everything was mutual, I even agreed- I was putting forth a lot of effort, and he was to busy to reciprocate.

However, I can honestly say, I was never clingy, never pushed a relationship, and was more understanding than most people are capable of his busy schedule. He repeatedly thanked me for being so cool and down to earth, which made me wonder: was being busy just an excuse? I've been so puzzled that this guy brought up being in a relationship on his own, but then balked at it months later? Any insight?

Unfortunately this was a little vague, since I wanted to make the post relatively short. I'm happy to answer questions down below!

*we are both in our early/mid 20s!