For those saying it can't be a new tank because he/she has i90 gear, you'd be surprised. My brother is currently leveling his WAR as his 2nd job (it's in the 30's somewhere right now), he already has a full set of i90 gear for when he hits 50 on WAR. Myth is so incredibly easy to get these days it's not even funny. Also you can buy i90 gear relatively cheap on the market board now too (compared a couple prices with the crafted i70 and i90, it varies widely. The i70 gear can be the same price as i90, if not more expensive. i90 gear can go for less than 100k now for the record. Chump change for some people, even if they're new).
On another note, yesterday I did Tam Tara (HM) with a WAR in about i75ish gear (half his gear was hoplite). Didn't have much issue with hate since the BLM (i90+) and I (BRD i92) weren't going all out with AoEs (though we probably could have, we didn't so it was less stressful on everyone. Just took a few minutes longer). We took it slow and told him to read the torn folios since it was his first time in the dungeon, was a fun run.