"Shootdodge" is a core feature in Max Payne, allowing the character to dive through air in slow motion. There is a key binding in the control options for "shootdodge only"—because bullet time is a finite resource which doesn't automatically recharge, diving in real-time would be a great way to move behind cover and gain distance. Max Payne simulates bullet ballistics and evading is always feasible. However, the "shootdodge only" move also enables bullet time as does "bullet time combo" and I can't notice any difference between these features. Both trigger the shootdodge move and enable bullet time, disabling it when Max lands.
I doubt that the game has two identical key bindings. I'm sure that my mouse has the corresponding buttons (MB 2-4) and that I'm hitting the correct keys. "Bullet time only" solely enables slow motion, as described. Game version is 1.05.