I'd go with this method, as befriending Evolution Studios or Phenom_Evolution will only be good if you can stay within three or so seconds of them (the ghost tends to fade any further ahead than that.) TT hot laps will indeed give you a succession of attainable targets to reach and beat.
That would be due to a large influx of new players now doing the event - it's like GT's leaderboards on the seasonal events. You might be high up in the first hour after they go live, but an hour later, everyone and their grandmother has put a time in as well, and some of those will be faster than yours.
In general though, with the track penalty changes made two months ago, a lot of people have learned how to exploit certain corners. Just looking at the times tells me that an exploit of that nature is likely responsible - see how the top ten or so times are quite a bit apart, and not fractions of a second, as would normally be the case.
Evolution are probably aware of this, as this sort of thing gets tweeted at them, posted on FB and all that - so in the meantime, practise, have fun and try different races - remember, losing doesn't affect your stats.