You're absolutely right; there is no "Talk" there of Hall, that is a mathematic proof which is a logical equivalent to the Max-Flow Min-Cut (Ford-Fulkerson Algorithm) that demonstrates and proves Hall's theorem.
There are several such logical equivalences relevant to your query: the Edmonds-Karp theorem, as mentioned earlier, Konig's Theorem, the Konig-Egervary Theorem, Menger's Theorem, the Max-Flow-Min-Cut Theorem (Ford-Fulkerson), the Birkhoff-Von Neumann theorem, and Dilworth's Theorem, among others. Any of those theorems may be proven true independently of one another, and any may be employed to prove any of the others based on the proof of the first. The same may be done for any of those theorems through any other of them without proving the operative theorem, but merely assuming it to be true.
Here is a brief article from PlanetMath.com illustrating an inductive proof of Hall's Marriage theorem, which could then be used to prove any of the other logical equivalents, which then could be used to prove any of the others, etc etc etc. That's the neat thing about
Combinatorics ; the math works.