  We study the semi-classical limit of the recently proposed coherent spin foam
model for (2+1) Lorentzian quantum gravity. Specifically, we analyze the gluing
equations derived from the stationary phase approximation of the vertex
amplitude. Typically these exhibit two solutions yielding a cosine of the Regge
action. However, by inspection of the algebraic equations as well as their
geometrical realization, we show in this note that the behavior is more
nuanced: when all triangles are either spacelike or timelike, two solutions
exist. In any other case, only a single solution is obtained, thus yielding a
single Regge exponential.
