NIN Monster used Mijin Gakure first thing

[Hazen]

Platform: PC
ISP: Cox
Type of Internet Connection: Wired Modem
Internet Connection Speed: Broadband
Date & Time: November 30th, 11:52pm Mountain time (10:52pm Pacific time)
Frequency: Happened once
Character Name: Hazen
Race: Elvaan M
World: Phoenix
Main Job: Thief
Support Job: Dancer
Area and Coordinates: Dynamis-Qufim in the north part of G-7
Party or Solo: In party with a SAM, but he was far away at the time
NPC Name:
Monster Name: Vanguard Assassin
Steps:
1. I used a ranged attack on an Avatar Idol
2. A Vanguard Assassin (Yagudo with NIN job) linked to the Avatar Idol
3. The Vanguard Assassin immediately used Mijin Gakure on me from some distance away.
4. I took precisely 2000 damage and died.
5. As a final note, I never acted on or damaged the Vanguard Assassin in any way.

I don't know if this was a fluke or what, might be a one-time thing and not worth looking into but monsters exploding the second they see you is... frustrating.

[Mirage]

So an assassin assassinated you. Who would have thought?! ;)

[Tamoa]

This has happened to me aswell, in Valkurm. I suppose in theory mobs can 2hr at "will" so to speak, just like we can?

[Mayoyama]

It could be possible that the NIN was melee'd on (but not killed) by other people/pets and so was responding accordingly... Its like when someone wipes to a mob and it goes passive, then you claim it.. the mob can potentially tp up front even though you personally haven't tp'd on it

(and yes, I know 2hrs/tp arent related as such, but its a plausible explanation of what happened)