Is the questioner liable for a fine concerning the bakery he rented to another person after he himself had first rented it, given that the current owner of the bakery denied responsibility and the summons was issued in the worker's name?

What appears is that the questioner is not obligated to pay anything from this fine due to not being involved in it. However, if he knew that the shop owner would not do what the worker had informed him of, he should have advised the worker and clarified the truth to him.