“This is some rescue (she mouths something like AH!) (cut to Han shooting) … you came in here didn’t you have a plan for getting out?”
Possibly after the first part she’s just getting bashed by Luke’s costume or the pyrotechnics caught her off guard, and then they just spliced the second half of the line from another take? There’s probably some editing and dubbing trickery here.
Her tone is that of a scolding statement, I think. Yet the words I hear sound like a sarcastic question.
IMDb has, ‘You came in here, but didn’t you have a plan for getting out?’
Wookieepedia, ‘When you came in here, didn’t you have a plan for getting out?’
What I now think I’m hearing is, first, either, ‘This is…’ actually drowned out by blaster fire, ‘… some rescue!’ or possibly just, ‘Some rescue!’
Followed by, something drowned out by blaster fire, possibly, ‘When you…’ then, ‘… came in here you never planned for getting out.’
EDIT I think my issue is, there doesn’t seem time for her to have said, ‘When you,’ but that’s the only thing that makes sense to me.
Sorry for tying up the thread with irrelevant minutiae. It’s just always bothered me, and I wanted to quote it on a blog post so it suddenly became particularly annoying.