Remainder beneficiary unclear in Will

I’d be grateful for views on the following. We are administering the estate of a client whose will left a right of occupation in her property to her second husband with residue to him. He died intestate estranged from his closest relatives a few months later and we now need to deal with the property. The relevant clauses in question are drafted as follows:

3.1 I give all my estate and interest at the date of my death in the property [ ] (my Property) to my Trustees upon the trusts declared in clause 7.3 of this will concerning the residue of my estate provided that:
3.2 If my husband is still alive at the date of my death my Trustees shall not sell my Property but shall allow my husband to live there as long as he wishes to or until he marries or cohabits for a period of at least 3 months with another person or dies.
3.3 [various provisions as to outgoings etc]
3.4 Once my husband gives written notice to my Trustees that he longer wishes to live at the Property or on his failure to meet the conditions for occupancy set out above my Trustees shall sell my Property and following the sale the net proceeds shall be held upon the trusts declared at clause 7.3 concerning the residue of my estate.
3.5 [provisions to allow husband to move house]

[clauses 4, 5 and 6 concern other specific gifts]

7 My Trustees shall hold the residue of my estate on trust either to retain or sell it and on the following trusts:
7.1 [to pay liabilities etc]
7.2 to hold the residue of my estate for my husband if he survives me
7.3 if my husband dies before me then to divide the residue of my estate equally among those of my children namely [ ] who survive me and if more than one in equal shares.

The will clearly directs the property to clause 7.3 which refers to the children. The will file explicitly confirms the client wanted the property to pass to the children and cash to the spouse. However, as clause 7.3 itself did not take effect (the husband having survived) does this cause an issue, or can we safely distribute to the children?

Surely everything passes under the husband’s will or intestacy (probably not to her children)? Looks litigious to me.