Given we observe that light do follows path A (gravitational lensing) instead of path B, is there any direct empirical evidence about how photons and gravity interact, other than stating that photons are massless particles when we observe massless behavior and massive when we observe massive behavior (gravitational lensing). I understand that energy can theoretically be turned into matter, but why would it behave like matter when is traveling in a massless configuration?
I'm not challenging that photons follow the observed geodesic trajectory (path A), nor do I challenge the mass–energy mathematical 'equivalence'. My question pertain to what 'other' empirical evidence do we have about massless particles traveling at the speed of light and behaving like massive particles 'at the same time'.
Couldn't it be argued that the gravitational lensing effect (ɡ) is the result of the space-time continuum itself being irreversibly 'attracted' (processed) by the mass (irrespective of any event-horizon), and not merely 'bended' (reversible/bidirectional) as traditionally described, without requiring the introduction of gravitons and massless particles exerting gravitational attraction beyond the local perturbation of the spacetime geometry.
If light photons are massless particles traveling in a vacuum, why is the direction of an angular photon permanently affected by a localized gravitational field as currently described by general relativity (path A on the figure - gravitational lensing).
Shouldn't they still follow a 'linear' (not straight) path within the projected space grid (path B on the figure), respecting the original angle after they exit the localized gravitational field? In other words, after they get out of the space-time bump.
UPDATE I: Thanks for all the input, I flipped the order of the question to clarify its depth.
UPDATE II: Added a clarification about geodesics and mass–energy equivalence.