Is this clematis wilt?

I've got a three year old clematis (Omoshiro) that flowered last month and has generally been looking fantastic until this week. I noticed 2 days ago that the leaves were looking a bit droopy, but given the torrential wind and rain at the time didn't worry too much; however closer inspection today and it's really not happy. All the leaves look like this - and it was filling out into a really nice busy plant until now.



Every leaf has the shrivelled black stem, and some are starting to brown at the edges. I'm assuming this is clematis wilt - is there anything I can do other than cut it right back?

 

Wilt is a lot rarer than people suppose. The more likely problem is that a slug or a snail has damaged the stem. Surprising how often this happens. Cut open a stem , if it has a purple stain in the middle then wilt it may be.
Question. Did it droop from the top down or the bottom up?

 

Thanks both.

Unfortunately we'll never know - I move out next week! I was wondering mainly for my own education, and so I can try to work out what I did wrong (and how not to do it again!) I'll cut it back and hope it recovers for the next tenants.

I'm not actually sure - I first noticed the top was wilted, but when I looked more closely the whole plant was already affected. I've had an awful slug year here but checking the stem I can't see any obvious damage there.