[css-syntax] "Consume a declaration" (5.5.6) leaves out a final "else" condition?

[amn]

Under list of steps described by 5.5.6 "Consume a declaration", point 8 says:

If decl’s name is a custom property name string, then set decl’s original text to the segment of the original source text string corresponding to the tokens of decl’s value.

Otherwise, if decl’s value contains a top-level simple block with an associated token of <{-token>, and also contains any other non- value, return nothing. (That is, a top-level {}-block is only allowed as the entire value of a non-custom property.)

Otherwise, if decl’s name is an ASCII case-insensitive match for "unicode-range", consume the value of a unicode-range descriptor from the segment of the original source text string corresponding to the tokens returned by the consume a list of component values call, and replace decl’s value with the result.

The issue lies in that there's two "otherwise" there (emphasis mine), both of which are conditional, meaning -- in plain language -- what if a declaration's name is not [an ASCII case-insensitive match] for "unicode-range"? What should a compliant parser do then? It's effectively a case of a missing "fallthrough" (default) behaviour specification, the way I see it. An omission of sorts?

Reading this with a different pair of (fresher) eyes, I understand the implication is that if neither of the clauses apply, the parser should "do nothing", but I suppose a remaining issue would be that there's actually several places in the spec. elsewhere which explicitly mention "do nothing", so lack of such explicit "do nothing" is somewhat of an inconsistency.