I this 700€ per month? Taxed?

Not bad, seems like you could almost live on that (outside large cities).

Well that person would be classified as a person with a disability pension of category such and such, and would actually have a good chance of finding a job because of quotas imposed on companies to recruit people with disabilities. Provided that this person lives in an area where opportunities exist (quotas not already filled up, not a too rural area, proper qualificiations etc).

But France may have an encouraging policy towards disability and employment, we're still far behind the UK when it comes to actually making life easier for people with disabilities. The new municipal library in Toulouse, the médiathèque, however, has done a great job for wheelchair access, braille books etc etc. But phone booths, public toilets, and even administration offices etc with proper access are still lagging.
 

We need to be clear on "disability". There are countless disabled people who can work and wish to work. In France, there are some incentives for employers to hire such people. They are simply classified as people at work, but the employer gets rebates on social contributions for them.

On the other hand, there's "incapacity", which means the person is medically considered unfit to work (until such time as the medical appraisal changes). Now that can be a "sink" for long-term unemployed persons the government would like to shunt off the unemployment stats. France doesn't do this; the UK has done a huge amount of it. (see these comments from the other day.)

ET has been in the forefront (long before McKinsey or the latest OECD report) in pointing out the importance of incapacity numbers in masking unemployment for propaganda purposes. Here is a diary I wrote about it last October.

Les stocks et les flux ?  You can be unemployed any number of times but are unlikely to be really disabled more than once (unless you're Djibril Cissé that is...).  Also, I'm willing to bet (though not look for figures, heaven forbid!) that a lot of the disabled went through a long bout of unemployment especially when the disability is due to a psychological condition.
My point is that the average Joe is being rational in fearing unemployment, which he will likely face at some point, which people around him are facing, as being more likely than being crippled physically or mentally.

As I comment above, we need to be clear about "disabled". A person in a wheelchair may be very capable of working, wish to work, find work. Same for other types of disability. These people suffer from some degree of permanent disability but are not necessarily classified as unfit for work.

What may operate as camouflage for long-term unemployment in the statistics is a medical decision the person is unfit for work. (For psychological reasons, for example, or chronic backache, etc). This may not be a lifelong decision, and will probably be subject to regular re-appraisal. But it takes an unemployed person off the unemployment statistics and on to another set that is not given public prominence...