Yeah, I've already ruled in my games that you don't get the extra from Dwarven Stoneblood on a miss. To me the steps go like this:
1. Player uses an invigorating power.
2. Player misses his target
3. Battlerager Vigor kicks in and grants the player 4thp BECAUSE HE HAS A CLASS FEATURE THAT GIVES HIM IT.(the Invigorating Power is the reason the class feature activates, but not the reason he gains the temporary hitpoints)
[...]
From a plain logical standpoint it's clearly the case that
both the class feature
and the invigorating keyword taken together cause the hitpoints to be granted.
However, every character taking dwarf stoneblood feat has the Battlerager Vigor class feature. It's a prerequisite. For the PC's in question thus, using an invigorating power always grants thp; both on hit and miss.
Since you gain thp whenever you
use an invigorating power (and hit or miss), and the feat increases the amount gained when you
use an invigorating power, isn't it reasonable for the feat to increase the amount gained both on hits and misses?
Consider also: Presumably the feat is written to be read accurately by the players of battleragers (they're the only one's that can take it), and from a battlerager's perspective, using an invigorating power grants thp, no-questions asked. From the perspective of the target audience, this feat most reasonable reads as increasing those thp gained by
using an invigorating power - not merely increasing those thp gained by
hitting with an invigorating power.
Finally, this reading doesn't strike me as being particularly abusive, so there's no meta-game reason (as far as I can see) to be reluctant to interpret it thusly.
