neighbor's CB500 MY2000

since the last two years I have a new neighbor
since the last year he felt in love in my CB
since last month he bought one

supporting the CB on the center stand, both tires (or tyres ?) are on the ground.
so much on the ground that is not safe.

tires at original size, rear shock absorbers original.

how it happens ?

I'd look at the front end, rather than the rear. The back wheel should be off the ground when on the centre-stand. If the front forks were sagging (a lot) the rear wheel might also hit the ground. Or if the front tyre was deflated. Does it have the correct centrestand?