The paint cracks are a good indication of compromised CF structure, but indications are more by way of warning than proof.

Paint is often more brittle than and cannot flex as much as the thin structure they cover. If you can flake off more paint you might be able to verify whether there's visible damage to the CF or, more commonly, the matrix holding it together. Sometimes, if you have well calibrated fingers, you can tell by gently squeezing the area and a comparable one nearby feeling for a softer spot. As noted, the tap test may also offer clues.

However, while it's easy to confirm damage, there is virtually no way to confirm that a CF structure is undamaged, shy of expensive testing methods. So, the best you can hope for is either positive confirmation that it's toast, or accepting that it seems OK and deciding whether seems OK is good enough.