it could be a hack that only affects his client, but doesnt reflect on anets servers. so go in with your 350 healing prayers, you'll still be healing for 16 or under.
2063 is the correct amount of damage a signet of judgment would do at level 512, assuming that the damage increase is linear.
Can someone with the smite attribute level GREATER than 12 confirm how much damage they are doing with their signet?
At level 12 the damage is 63. If the progression is linear, then the damage is 67 at level 13 smite or 71 at level 14 and so on (base 15 damage + 4 every level). If, however, someone comes back and says that the damage is NOT 67, and is actually anything else, then the picture is faked. If however the damage IS 67, then we are no closer to knowing the truth but at least we tried.