When someone prefixes a sour message with a positivei qualifier, the intent isn't to lie, but to reassure you.
If I plainly stated "We're going to have to work on clauses 3 and 4 before we can move forward," you may believe that the issues with these clauses are more severe than I actually believe them to be. Or you may believe that my patience has run out. The qualifier "I'm not saying the deal is off" is intended to express a sense of furthered interest in making the deal work. I "invested" more in my statement as a gesture of good will. An indication that I'm not being dismissive. Have you ever had someone ask you why you were "being so short"? Brevity shows a lack of interest or patience.
It's called subtlety, and it seems lost on a lot of people these days.
Actually putting, "I'm not saying the deal is off..." makes me think the deal might be off if I don't 3 & 4. Your other statement, without the qualifier, simply makes me think we need to work on 3 & 4.
The qualifier in this case seems to be an attempt to prime the listener with the fact that this deal is not a sure thing still.
And people are misunderstood all the time. You'll read in to it whatever you want to, but it won't change the way I feel when I say it. It's your job, as the listener, to judge the way I mean it. The simple fact that I have said it doesn't make it one way or the other. Those who are adept at these types of judgements are the ones who move deals forward. Those who cannot get stuck in a cycle misinterpretation that results in a failure to negotiate an agreement.
I'd read this as; the person actually did enjoy the movie .. but could have enjoyed it more if it wasn't so OTT. No deception involved.
To read this kind of thing, it's always important to think about what the person's intent is. If someone's behaving in a Machiavellian way, it's _all_ about intent (and possible incentive).
I would just say, "The action scene was a bit over the top." If the person hears that and thinks I didn't like the movie, that's their mistake. Your first phrase still leaves the door open for you not liking the movie and it adds no clarifying information.
I'm not saying that the deal is off, but we're going to have to really work on clauses 3 and 4 before we can move forward.
I interpret that statement as "unless you come my way on clauses 3 and 4, the deal is off."
For me, it's hard not to read two statements, joined with a 'but', and not interpret the first statement as a 'lie'.
[1] irony intended