Should I be mad at him?? 5 STARSS?

My best friend (a guy) and I (I'm a girl) talk for hours a day, but I havnt seen him for about a month because of our busy schedules. I go to a golf club about a 10 minute walk to my best friends house. Today I walked over there with my sister, and then called him and told him to look out his window. He told me he was on a run, and was on a street about 5 miles away from where his house with. So we started walking away. Then we decided to go back the other way, which meant we were walking by his house again. He then called and commented on our old t shirts we were wearing, and then hung up. I then called him, laughing, asking if he was really home. While we were talking, he walked outside to the end of his driveway. My sister saw him and chased after him. Just as he was shutting his garage door, my sister put her foot underneath it, making it go back up. He then started throwing golf balls at us. Yup. ACTUAL GOLF BALLS. He then said "I'm going to go take a shower, I just went on a run." And closed the garage door behind him. We stood there confused, while his annoyed mother came to the door to find out what was going on. We left quickly before she could say anything. This just happened. I'm so mad at him. I haven't seen him in a MONTH, and we've been trying to make plans for like forever. He even asked me to walk his dog with him yesterday, but I couldn't. I don't know if I should be mad, or should even still be friends with him? Do you guys think it was a d*ck move? And why did he do it? Thank you!!