The IgG test for HSV 1 misses 30% of infections so I’m not surprised about that.
If he knew he had HSV 2 and didn’t tell you and you acquired it, you have a legal case against him if you wish to pursue it. Your negative IgG for HSV 2 and subsequent positive swab says this is a new infection and would be essential for a legal case to move forward.
Terri