Certifying distributed algorithms (CDAs) are a runtime verification method for distributed systems. A CDA computes additionally a witness to an input-output pair – a correctness argument for the pair. The witness is verified at runtime by a distributed checker algorithm. In this paper, we apply CDAs to an industrial case study of collaborative transport robots serving machines in a factory. In particular, we present a certifying variant of a distributed bidding algorithm executed by the robots to assign transport jobs amongst each other. Furthermore, we introduce overlays in order to organize the communication of the distributed checker, and compare them regarding their intrusiveness.