Geeze....I am glad my ex didn't get advice from this forum...LOL
He split 3 months after we bought the house so there was NO equity....in fact, a partition would have cost BOTH of us signficant bucks. Our loan was FHA...we came out of closing owing more than the FMV of the home.
I refinanced 3 or 4 years later and he didn't have a single problem with signing a quit claim at that time. I maybe should have done it sooner but neither of us even though of it until that first real drop in interest rates (thats why I refied....we bought when standard interest rates were 10 3/4...and that was back when 8 1/2 was a BIG DEAL). If we had had any equity when we split up I would have felt that something was due to him, but we sure as heck didn't.
Of course he paid child support...he felt it was his responsiblilty to do so but would never have considered that the fact that he paid child support meant that he paid my mortgage..
Of course we didn't divorce until about 8 years after we split up, and had totally divided our financial lives long before then (he had purchased a house too)...and neither of us would have ever DREAMED of trying to profit from the other at the time of divorce.
I don't see this case as being any different. If there was equity when they split then he is entitled to something....and some interest/appreciation on that equity since he could have used the money to invest in something else had they handled it at the time of divorce.
However, expecting him to get 50/50 when he didn't contribute to the mortgage or the upkeep is patently unfair....and would be patently unfair if the roles or genders were reversed.