I think what you may be interpreting as bending is actually the illusion of bending. In several places I am playing legato (playing smoothly and running the notes together) and using chromatic notes and scales to imitate bending.
Because I am blowing hard, I think some other notes are sounding a bit thick and wavy during the attach and release.
I am still working on deliberate bending, but it is not easy. It can be done, but I am not sure we (melodica players) will ever be able to bend notes as much as a harp player. That would be a dream come true.
I think you actually posted one of the best examples of note bending I have heard.