Well, the deposit isn't really for covering missed rent payments, it's intended to cover landlord's losses / damages and costs of decoration. If you don't pay it and he has contact details and addresses then he can pursue you through the Sheriff court on the grounds of breach of contract. You'd then have to argue your side of things as to why you didn't bother paying it.
If he doesn't have any way of contacting you if you do a bunk then fair enough, but you've definitely lost your deposit then. In my experience, never assume anything. Pay the last month's rent and then ask for your deposit back. You never know, he may hand it over, or at least some of it after he's deducted his reasonable entitlement for costs etc.
If you use a large chain letting agent in future and they ask for a reference from your most recent landlord then you'd be fucked if you do a bunk with his rent.
Edit to add: remember also that the terms of your lease should have specific clauses for termination, so make sure you know the proper procedure. Most leases nowadays are standardised in Scotland, a 6 month affair with allowed periods of notice for tenants and landlords to serve notice to quit (usually 2 months advance notice for the landlord serving notice on the tenant and 1 month's notice for the reverse). The reason I bring this up is because leases don't just "expire", they roll on as before even after the time periods stated in the document have elapsed, unless either party changes the terms of the lease by way of specific written procedure.