The answer on this question is yes because whatever you do when you are angry or upset you will make at least an error or two. It does not to have to be speaking or writing. But we will stick to these two. Even in your native language you tend to mix things when affected by anger. Additionally, when you are angry or in high emotional state you can hardly focus or take it easy and slow like you would do when you at peace. That said, it is normal to have some problems in conversing. When it comes to a foreign language that you learn or have to speak situation is usually worse, because another factor is finding its way to your abilities and that is insecurity that is growing bigger when you are upset. Example for this is when you are watching your favourite team playing football. If they score or concede a goal you are probably going to scream something on your mother's tongue and not in that other language you are learning or have to speak. Reason for this is because your brain is set by default to produce thoughts in your language and you barely have to think, it is already there.