Verner explains the exceptions to Grimm's Law

node

Karl Verner published an account of the residual Germanic words in which Grimm's Law appeared to fail, showing that the outcome depended on the position of the Proto-Indo-European mobile accent — a feature preserved in Vedic Sanskrit but lost in Germanic, which fixed its stress on the initial syllable and destroyed the conditioning evidence. A class of exceptions was thereby converted into a second regular law by appeal to a property recoverable only through reconstruction, which remains one of the strongest arguments that reconstruction describes a real earlier state rather than a convenient notation.

A node is not a place. Drawing it on a map would assert something about the world that no stored fact supports.