The etymology of br' is obscure, and as James Barr (_The Semantics of
Biblical Language_), etymological considerations are only marginally
helpful in considering the semantics of a lexical stock of a particular
semitic language. Usage is definitive.
In that vein, it can be easily verified by anyone with access to a
Young's, Strong's, or Englishman's concordance that God is the ONLY
subject of br' in the Qal. The Pi'el and the Hiphil, which contributed to
Gesenius' conjectured etymology, are clearly in a different semantic
range and are of little or no relevance to the determination of the
meaning of br'.
However, it may be seen (again, from any concordance) that while God alone
is always the subject of br', it is not the case (as some authors--
references escape me at this point--maintain) that br' is "creation out of
nothing." Thus br' in Gn 1:1 seq. does not entail ex nihilo creation.
See U. Cassuto, _Commentary on Genesis: From Adam to Noah_, or Henri
Blocher, _Revelations des Origines_ (English translation available from
IVP), among others.