FOX FLOAT CTD Evolution oil leak :(
I am certainly no expert in shocks, only ever stripped one model a couple of times...

Is the shock holding pressure?  If so, its the wiper seals leaking not the aircan seal - check the damper body for scratches/damage. If not external damage I would re-service the shock pay special attention to the damper body condition and that the damper seals were correctly reassembled.

If the shock is loosing pressure, it will be the aircan seals. Check the internal surface of the aircan for scratches.