And I raaaaaan, I raaaan so far awaaaayyyy

[Frieza_Prexus]

I also think it's relevant to point out that the "rule" has been First to Engage. This does not necessarily mean that being first on the aggro log is that you are first to engage.

Yes, the aggro logs and FTE have been treated very synonymously, but there is still argument that a distinction exists. Perhaps, the aggro logs are simply one informative facet as to who got FTE, though they have been indisputably convenient in making determinations when no GMs are present.

Perhaps an encounter such as CT already DOES have a mechanism to determine who has FTE. Under this theory, TMO's raid engaged the mob first. Even though the logs were clean at the time of Scorchin's DT, it is indisputable that TMO engaged with the first DT. There is no other reasonable explanation for the guild's activities in taking the first DT and charging the mob OTHER than intent to engage.

In short, first to engage is not necessarily synonymous with being first on any particular instance of the encounter logs. Perhaps the rules were followed to the letter here. Perhaps first to engage is a broad concept that can, from time to time, require a factual inquiry into the situation.