If I were in your husband's situation I would follow Pratoman's advice and first get a second opinion on the pathology from Epstein at JHU. The reason is as follows. Epstein et al, in a study in 2012, showed that "Of over 14,000 totally embedded radical prostatectomies from multiple institutions, there was not a single case of a GS ≤6 tumor with LN [lymph node] metastases." (I can provide the reference, if you want it.)
If Epstein does corroborate that the pathology is indeed G6, you can speak to him directly and ask him what he would do given the circumstance that RT is undesirable. (If you do get a second opinion, ask for Epstein to do the evaluation himself.)
It is not surprising that your husband's PSA is increasing, given the positive margin; however, even a small amount of G6 PCa can generate a large amount of PSA. In my case, my PSA climbed to almost 10, even with a very small amount of G6 cancer.