There is a news story out about older fathers being more likely to father autistic children than younger fathers.
It seems to me that you can't draw any conclusions just based on the information given - more information is needed. It may be that - as some have suggested - that environmental conditions could contribute to autism. So the longer a father was alive - the more likely problem toxins could accumulate that could be passed on (like mercury that accumulates in fish).
There is also some correlation with problems with immune systems and with diet - it's possible that that could figure in somehow.
It is also thought that there is a genetic link - and there is the idea that parents with High Functioning Autism (like Asperger's) are more likely to have children with Autism. It seems quite likely to me that parents (and esp. fathers - as males are thought to be more likely to have Autism anyway) with High Functioning Autism may be far more likely to have children later in life. That would be something to study. So it may take them longer to get that computer programming job, to decided to get married, to settle down into a routine where they would decide to start a family.
Or it could a combination. The study doesn't look at the why. I don't think it makes sense to assume that having children later in life - by itself - would be a cause for autism in children - without putting together all of the pieces.
I noticed this website has a collection of articles on related topics - like "Study Addresses Schizophrenia Link" (also about older fathers). I have seen other studies that connect Schizophrenia to where you live and what you eat - which could also be toxins and genes. Some people see links between Schizophrenia and Autism.