In theory, there is no "point" where this is the case, as it should "always be"
You have a 1/1 contact that is a drug dealer in the barrens. The guy sells low quality novacoke and nothing else, but you get information from him and pay him for it. It's a functioning business contact. Nothing more.
So, you can call him for information or coke or whatever you want at (almost) any time. But, just like you have his number in your phone, he has your number in his, and has every right to call you for a job.
Now, you have the right to turn down that job, for either legitimate reasons (Not enough money, on another job at the time) or illegitimate reasons (don't give a shit) but be enough of an asshole and he will stop being your contact. Be nice to him, and loyalty goes up, and even connection if you feed him the right way. (Give him some money on loan so he can get better equipment for better drugs. Take out rival drug dealers. Send good clients his way. Defend him from other runners who are hired to take out rival drug dealers)
Contacts should ALWAYS be a two way street, or at least, should always have the understanding that there is the potential for it. 1/1 Druggy might not really need the help of a prime level hired mercenary, nor the budget, and he may never feel the need to call you, but he should always have the right to.
Even if its just something like "Hey, boss, word on the street is you's gonna be shooting up that mafia safehouse. I'll buy any coke you find over dere. Extra payday for you, more coke for me, and you don't have to worry about finding a fence!"
So, no, even at 12/6, the pope is still your contact. Sure, you're his contact as well, but at no point does he stop being your contact and it becomes a one way relationship.