Can't tell the system thickness from the photo, (it would be nice to hold the end of a tape measure up to the stem when taking pictures like this) but it seems from the other pics that the stucco was installed after the stone work. Ideally there should be a j-metal stucco stop where all stucco meets dissimilar materials, in this case, because of the in & out of the stone, the stucco sub or the designer decided not to do it.
If all the WB's and flashings are in place, (hard to tell w/o destructive testing) it should be ok, unless there is other evidence of moisture intrusion on the interior, you might suggest it as an area to watch for future problems.

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