Last night, my players were battling a hob, who had 4 stress boxes, plus 4 more from his inhuman toughness. One of the characters hit the Hob before they knew it was fae and did 5 stress. The inhuman toughness absorbed 2, and its three stress box was filled. The other, having been informed by another character that the beast was fae, hit it with a steel IV stand, inflicting 9 stress. The Hob took its mild and moderate consequences, reducing the stress to 3, and with the catch had to take that three, rolling up to the 4 stress box. After the rest of the exchange, the first character, now armed with the knowledge that she was facing a fae, picked up a scalpel and leapt towards the Hob, planning to drive them through its eye.
She did 9 stress, it took a severe consequence (the scalpel drove through its hand), and had to take the other 3 stress. That three stress rolled up to the 5 stress box, and took the hob out (she pinned its hand to his eye, driving the scalpel into its brain).
My question is, was the hob taken out at that time, i.e. does the catch reduce the number of physical stress boxes to the normal amount? It actually had 8 stress as I said, though 4 of those came from its inhuman toughness, that the catch had been satisfied for, so I presumed that the stress doesn't apply either. One of the players was glad that the others had taken the hob out, but concerned because he hadn't read it that way, and was a changeling that this affected also. Reading the book again (YS185) I see that it could be interpreted the way that he was, though I think that my interpretation is correct.
The Catch [+varies]
Description: Your Toughness abilities are limited in some way.
Effects: The Catch. You must specify something that bypasses your Toughness abilities.