The video clearly shows a microphone placed a few inches from the soundhole fo the guitar, but I suspect there might be additional amplification as well.

There could be a cord coming out of his strap-button, connected to some kind of under-saddle pickup ~ the picture is too dark to see whether or not anything is there. I suppose he could even be using a wireless pickup-to-amp connection ~ that's certainly not unheard of for electric guitars in rock bands, I see no reason why a similar setup could not be installed in an electro-acoustic.

Hammering-on and pulling-off strings on an acoustic guitar is usually audible only when the string has just been plucked/picked immediately before the note played with the left hand only (hammered or pulled). The kind of one-handed playing seen in the video is relatively easy on an electric guitar but not on an unelectrified acoustic.