I never said inequality causes job losses. On the contrary, job losses cause inequality.

Job losses as the mechanism of inequality would very little nothing to do with Piketty's claims, which are about concentration of wealth at the very top due to intrinsic properties of returns on capital. Piketty's theory doesn't involve this either causing or being caused by job losses. So seeing unemployed people and taking it as confirmation of his work would be incorrect.

(In any case if you are correct about direction of causation, then surely we should worry about how to reduce job losses than how to take wealth away from the rich.)

But countries like France and Spain have persistently high unemployment rates yet much lower inequality than countries like Singapore and Hong Kong.

How do you explain that?

Deliberate government policy to prevent inequality.