kr6yl,
Thanks for the questions. Sorry to read of your husband's ordeal.
The ECG cannot be interpreted in isolation. "Mild" ST elevation
can be quite concerning or not concerning depending on the rest of the information. Such things as the character of the pain, how the pain compared to the pain prior to the angioplasty, the shape of the ST elevation, whether or not the ST elevation came and went with the pain, how the ECG changed over time, what the blood markers showed, etc, all figure into whether or not the ST elevation is important.
Talk to your doctors. If you are having difficulty speaking with them, seek another opinion.
Hope that helps.