Yes, the behavior you described can be considered rude and disruptive to the conversation. When someone interrupts an ongoing conversation to point at something and shout, it shows a lack of consideration for the people who are talking. It not only disrupts the flow of the conversation but also indicates that the interrupting person is prioritizing their own interests over the ongoing discussion.
In social settings, it's generally expected that people show courtesy and respect for each other by waiting for an appropriate moment to interject or bring up something unrelated. Interrupting without a valid reason can be seen as impolite and may make others feel ignored or disregarded.
If your friend frequently does this, it might be helpful to gently bring it to their attention and discuss how their behavior affects the group dynamics. Encouraging more mindful and considerate communication can lead to more positive and enjoyable interactions for everyone involved.