Is this a helmet defect or not? I bought a new Giro Savant helmet online and, after unboxing, noticed that the EPS foam seemed to be quite jagged and uneven at the intersection with the dial system (see photos below).


This does not look like damage to me and the foam was probably cut that way. I have seen a few images/unboxing videos online that also seem to have quite jagged foam at the intersection, so this suggests that maybe most of the Savant helmets are like this.
I am not bothered with the cutting of the foam if it is just cosmetic but obviously I would need to know that the helmet is not compromised before I can use it.
I would really appreciate any advice so that I can determine whether the helmet is safe to use.
The jagged and uneven edges you are seeing around the straps are merely cosmetic. At best they are at the minimum tolerance for manufacturing quality and at worst are an isolated case of tolerances going wrong during production.
Either way, as long as the integrity of the foam in the helmet is not compromised (by virtue of crashing or the like), then it is safe to use. Happy riding!