There are some real idiots about! I would be interested to hear what happened after this, what the other pilot said, what, if any, action was taken. Was there ATC at this airport? If so, what instructions had been given? Clear to land (guy filming)? Hold before active runway (a/c on the ground)?
Agree the landing pilot could have decided earlier to go around, but we are only talking a couple of seconds or so.
In the end it was a well executed go around that prevented a certain accident. Criticising the landing pilot for a couple of seconds delay is, in my view, wrong. We should concentrate on the muppet who entered the runway!