Difference in BJT Incremental Resistance between DC circuit and AC circuit
The problem touches the question: Can there be a difference between both measurements because the "incremental" resistances are not equal? It think, the only differences can only be caused by 

(a) thermal properties and/or 

(b) capacitive properties of the pn junction. 

In this context, the measurement times (first experiment) and the test frequency (second experiment) are important parameters.