As long as you feel good about the decision...you made the right decision. Do you have previous history with him that makes you lean toward 3? I really think he is north of 3 based on only those 2 pics. One positive is that your brother may be able to harvest him and I'm sure he would be so thrilled to do so....that is a really good buck. Another positive, is that he may survive to net year...maybe you build a collection of pictures, and pick up his sheds and really build a good history with him, that may make a harvest next year even more memorable. I have a buck around my property that I now have almost 4 yrs of history with...ages 3, 4, 5, and now 6. I have sheds from ages 3, 4, and 5. I almost got a shot at him when he was a 3 yr old.....and although i was disappointed at the time...I am very glad it happened that way now. I saw him from my stand once when he was a 4 yr old, he completely disappeared as a 5 yr old, until i found his sheds on the neighbor's, and then got a few pics of him early this summer. I used his 3 yr old shed to propose to my wife, and i found his 4 yr shed the day i found out that i was going to be a dad! Part of me really wants to put an arrow through him this fall....but a part of me doesn't want to....I honestly don't think i will enjoy shed season in the area as much with out the hope of finding another one of his antlers! As much as i am a die hard deer HUNTER....i am also a die hard SHED hunter.
I was in a similar situation to you last fall....my son was delivered on Nov 18th. I shot my buck on November 9th. As it was getting down to the wire, I'd be lying if i didn't tell you that I was starting to feel some pressure, because I knew after the 18th hunting would be the last thing I would be able to allocate my time to.