I think the issue for the lender would be one of acting on the security. If for example this was a joint loan on the family home, and one party died, the lender may have to wait until the 2nd party passes on.
They would be declining the application on that basis.
If its structured properly, then of course some lenders would go over 70.
The equality angle might work, but the test would be what would a 'prudent lender' do and if it all hangs on one party remaining alive, with no other security than the residence .. it probably wont fly.
Also on any of the equity release products, one with a variable rate (though much higher than normal) would have the benefit of taking repayments without penalty. (Though the rate is higer than Life Loan)