Every video published at tasvideos.org is required to have a disclaimer at the beginning of the movie file that it is a tool-assisted movie and not meant to represent human skill.
I respect a lot of the TASers. It used to simply be a matter of single frame advance making "perfect" speedruns possible, but these days it's almost competition. Who can shave off the most time by using game glitches or physics to find the optimal paths. Also, some people monitor memory values and go for luck manipulation. For example, the Dragon Egg submission. Having a fully powered dragon makes most of the game go much more quickly, so by manipulating the random/luck elements in the game Adelikat managed to upgrade his dragon all the way right in the first level to facilitate speeding through the later levels. The down side is that Dragon Egg is actually not all that entertaining a movie when TASed. Other games are much more entertaining.