Being dishonest on your application or interview is grounds for dismissal.
But also consider - Is teh experience relevant to this job? Does he have what it takes to perform? Does he have ur specified exp and qualifications?
I do exclude what is not relevant to the job and adapt to the job specification, only if i have teh experience and qualification. For example i used to be a teacher, and i am applying for an admin post, then i leave out the teaching experience and qualification becos it is not relevant. But I have indicated in teh interview that my previous exp was in so and so.
We adapt our CV's all teh time to suit teh job requirements.
Be careful people do have a habit of protecting poor performers, and doing down the good ones, no matter how they came to be gainfully employed. What is it worth to you to see him penalised?