The short answer is that "all" refers to the whole of something (if uncountable):
I've drunk all the water from this glass.
or the whole of a collection of things (if countable):
I know all the students in this class.
and "any" refers to some amount of something (if uncountable):
I've drunk some water from this glass.
or one or more things of a collection of things (if countable):
I know some students in this class.
I imagine the reason that makes the example:
There was something false in all this.
confusing is that "some" and "all" appear in the same sentence.
To dispel the confusion, one has to understand that "all this" and "something false" do not refer to the same thing.
Let's put the example into some context. Imagine, for instance, that I'm a mathematician that has written a proof for some impossible theorem. In this context, "all this" means "the proof", that is, the whole chain of reasonings that led me to the impossible theorem. "Something false" is the part of the proof, that is, the reasoning or reasonings in the proof that are wrong and that led me to a wrong conclusion.
One could also ask whether it's possible to use "any" in the example (since "something false" refers to some amount of a something).
The answer is yes, but bearing in mind that "some" is used in affirmative statements, and "any" is used in negative statements and questions. For example:
There wasn't anything false in all this.
Was there anything false in all this?
1Your examples are hopelessly ungrammatical. – FumbleFingers Reinstate Monica – 2014-06-23T12:22:21.137
Well, it would be nice if you would point it out and help ;) – Mnescat – 2014-06-23T12:24:02.477
I'm ambivalent about answers posted by non-native speakers containing "non-idiomatic" usages. Thus, several or more strikes me as an unlikely expression (*several or all* would be natural there), and on purely semantic grounds I think you should have used something like indiscriminate rather than picky, which means the precise opposite. – FumbleFingers Reinstate Monica – 2014-06-23T12:47:02.470
Thank you for the clarification on my answer. I'll take some time to look it all up and see if I can learn something from it. – Mnescat – 2014-06-23T12:53:33.403
2
@ Mnescat: Please do. I don't want to come across as a grumpy nitpicking schoolteacher, but there's recently been some discussion on meta regarding "errors/shortcomings" in questions, answers, and comments. I'm inclined to think some faults in questions can reasonably be left "as is", but that answers should be exemplars of valid English usage on ELL and ELU (the substance of your answer is obviously correct, as I'm sure you know).
– FumbleFingers Reinstate Monica – 2014-06-23T13:52:21.900...having said that, I've cancelled my downvote because the most egregious fault has been corrected. But at the moment I'm not inclined to upvote because of the other two points which bother me. – FumbleFingers Reinstate Monica – 2014-06-23T13:55:10.990