Looking for a little guidance here, in case we're overlooking a clear answer.

When a Psyker's comrade uses Ultimate Sanction to force a reroll on the Psychic Phenomena table, if the Psyker has the Favoured by the Warp Talent, does the Psyker get to roll just once, or does he get to roll the normal dice and the FbtW dice and choose the result he wants?

We're really looking for a legalistic run-down, not just a "gut feeling", if that's all right.  It seems like a strong case can be made both ways.

Thanks!

I'd personally say he gets to roll the Favoured by the Warp dice, since it doesn't provide an exception to when those dice get rolled, it just says you get to roll twice whenever you roll on the table.

Favoured by the Warp states: "Whenever a Power Roll results in Physic Phenomena…"

whereas Ultimate Sanction states: "re-roll any result on Table 7-2".

So my interpretation would go like this.
Roll for Physic Phenomena and for Favoured by the Warp, should you dislike both results you may use Ultimate Sanction to reroll any one result.

You pay to costs for Ultimate Sanction once and then decide which of the results to reroll, you could pay twice to reroll both of them but you can't reroll one of them twice.