My RIS was also flat. i went ahead and reviewed it, but be ready, i'm honest.
i think i may take the other bottle out of the fridge, add some super high grav yeast and recap.
if i remember correctly, you said this came to 15%??? that could be part of the problem
I reviewed your other beers as well, here goes...
RIS 8/8/8
Aroma: Chocolate nose
Appearance: zero head, otherwise good color
Flavor: Good beer but needs more age or yeast @ bottling maybe, slight alcohol bite
Mouthfeel: Flat, 0 carbonation
Overall: Sorry, man...either bad bottle or problem w/bottling
Mirror Pond Bottle
Bottle was slightly underfilled
Aroma: Nice floral aroma on pour, some citrus
Appearance: poured w/thick head, thick body could be clearer
Flavor: A little sweetness coming through the bitter. Unpleasant fruitiness
Mouthfeel: Nice mouthfeel, proper co2...again a little thick
Overall: Allow more time for clarity in primary and secondary. Needs conditioning time in general. I can't get over the floral+fruity...check your ferment temp as i think it has some bad esters
Sorachi Slammer
Aroma: Citrusy, sour aroma...DEFINITELY sorachi
Appearance: Good head dissipates immediately. Beautiful color, but hazy
Flavor: Very clean, extra citrusy...maybe some pine
Mouthfeel: Nice, could have a little more carbonation, i think
Overall: I don't like sorachi, but i think this was a very fine use of the hops!
i think if you give your beers some more time in primary and better control your fermentation temperatures it would make for some wonderful beer. hope that helps.
thanks very much for sending me these. your sorachi beer is good...mine was a nightmare