Kya Hoga Contract Ke Badle Administrative Law Mein?

Maine socha tha I understand Contract, and then the paper happened 💀 I'm trying to make sense of Administrative Law and found a doubt in my mind. Here's the situation:

In State of U.P. v. Ashok Kumar Singh (2013) 12 SCC 645, a 8-judge bench of SC decided that when an administrative action is challenged, the court's duty is to quash the action if it is found to be malafide or arbitrary. But then, in Centre for Environ. Justice v. Union of India (2005) 3 SCC 214, SC laid down that the court should not substitute its own discretion for that of the administrative authority.