This is a typical case of mansplaining. Our style of communication tells the other person how much or little they are valued. Often men are not aware of their own inappropriate messaging style. This can come across as a lack of respect, especially in a scenario where the recipient has superior expertise. If you are at the receiving end of this it’s crucial not to get distracted by this communication style. Do not accept it as just another example of gender bias but respond to it when it occurs.
The best way forward is to ask questions and show interest in the topic itself. Use this as an opportunity to showcase your knowledge and professionalism! Do not fall in the trap of becoming emotional and belittle your colleague’s lack of expertise. Use a warm and understanding voice tone while putting forward your arguments. This is how you establish yourself as a calm, reasonable, rational and competent expert in the room.
If there is no such opportunity or you simply find the situation too overwhelming – simply approach your colleague at a later time. Choose the right time and make sure no one else is around to avoid him losing face. Tell him in very clear words that his comments devalue you – as the expert. Do ask him how he would feel if this would happen to him. Always avoid inflammatory language and words such as “ever”, “never”, “always”, ”unfair”, “hurt” and “disappointed”.
Try to make an introductory statement that you value him as a colleague and that you respect his expertise, even if this may not be 100 percent accurate. It will put your coworker at ease, which is a precondition for people listening to what you have to say.