Does the description "melted fingerprints" mean that there is glass filling in the stone? I have read an EGL report, which states the ruby is heat treated with evidence of "melted fingerprints."
fingerprint type inclusions are a common type of inclusion that look like a portion of a fingerprint floating in the stone. Heating the stone can melt the inclusion, some of which can get absorbed into the crystal matrix, but still leaving a lesser trait. I would think the melted fingerprint inclusion was one of the criteria that told them the stone had been heat treated.
I would always defer to Richard Hughes. Certainly if the fracture containing the fingerprint reaches a surface it could be flux healed / glass filled. If the inclusion is not surface breaking there is no way for the glass or flux to get in.