But it doesn't say that it doesn't override the 'empty square if possible' bit.
Ah, but it also doesn't say that it doesn't
not override the 'empty square if possible' bit!
I suspect even the writers of the BB rulebook didn't anticipate the degree to which they would have to state the obvious to satisfy their audience of strategy gamer nerds.
At any rate, here's how I'd put it: The rule referring to push backs on page 10 is the general rule, and applies to all push backs. The rule referring to Side Step applies to all push backs in which the pushed piece has Side Step. Does that mean that the general rules about pushbacks don't apply at all? Looking at the text, the answer is a clear 'no', since the rules for Side Step
modify the rules for push backs. Now there are two possibilities:
1. Where the two rule paragraphs "collide", i.e. dictate different outcomes, the Side Step paragraph takes precedence, naturally, since it's the more specific rule (lex specialis derogat legi generali).
2. Where there is no such conflict - because the Side Step rule paragraph
doesn't say anything different - the original rules for push backs remain in effect.
Is 1 or 2 the case here? Let's look at the letter of the word. The Side Step rules say "any square, not just the three squares on the push back diagram", but don't explicitly say that they override the push back rules insofar as pushing onto occupied squares vs, empty squares is concerned. Is that enough to conclude that the Side Step rules are intended to override that rule? Considering the same sentence refers to the push back diagram - which in itself only denotes the three squares that a player could be pushed into
if they were empty, it's at least doubtful.
Fortunately, the interpretation of law
is not limited to the letter of the word. We can take other factors into account, such as general principles of the game of Blood Bowl - one of which is that only one player can occupy any given square at the time. We can take into account the intent of the rules writer, we can take into account common sense.
tl;dr: RAW is only one aspect of rules interpretation, and pretty much always trumped by RAI as long as common sense is applied.
Applying common sense also isn't cheating.