Ifound this information regarding slabs for the Texas area, if it helps.
My experience with slab cracks, since I personally worked with concrete all my life is that I would not be alarmed with what you saw and would just note fine line cracking in the slab was observed.
Not knowing how the slab perimeter is supported, I would have to say it is not attached to the exterior foundation.
Hope this helps.
(A) A floor over pier and beam foundation shall not deflect more than L/360 from its original construction elevations and have that movement create actual observable physical damage to the components of the home identifiable in Section 5.3 of the ASCE Guidelines.
(B) If a floor over pier and beam foundation deflects more than L/360 from its original construction elevation and the movement has created actual observable physical damage to the components of a home identifiable in Section 5.3 of the ASCE Guidelines, a third-party inspector’s recommendation shall be based on applicable remedial measures as described in Section 7 of the ASCE Guidelines.