No. Thermodynamic laws hold regardless of the mechanism; that's one of the points of thermodynamics. If a gas in a state (p1,v1) is brought reversibly to a state (p2,v2) in one experiment and brought irreversibly to the same state (p2,v2) in another experiment; the entropy of the gas is the same in both cases.
The mechanism can be treated as a black box, which is one of the uses of thermodynamics. It can also be used to analyze the mechanism. The reality is that you need a mechanism to go from state 1 (p1,v1,T1) to state 2(p2,v2,T2) -- except in rare circumstances (e.g. natural weather conditions). Also, the notion of reversibility has everything to do with the mechanism. To allow the change typically you have to apply work that is constrained in specialized ways enabling the process to occur. The mechanism is the device that constrains the energy.
Perhaps your interlocutor is unfamiliar with the term "state variable"......