You are absolutely right. Dyslexia is a 'language processing difficulty' and the dyslexic brain is 'wired' differently to the non-dyslexic brain which can mean that some have difficulties expressing themselves verbally )(sometimes due to word retrieval problems). Being a Disability Officer does not make you a dyslexia expert.
I think that many people are led to believe that all dyslexics are good verbally and just can't get their ideas down on paper - this is true for many but there are people like you who get their words jumbled when they speak. I see it every day in my job - I am a dyslexia specialist.
Ask him if you can do the presentation in front of him and a couple of others who you feel relaxed with. This way you are fulfilling his criteria but not flunking it due to nerves. Hope this helps.
