Arcing through loose wires is the biggest cause of electrical fires because of the heat generated through faults which usually ignites third party waste and not the electrical components themselves.
I have experience of this and cables can arc/burn without either tripping an rcd or blowing a fuse.
All that causes a fuse to blow is excess current. The gradual arcing and burning in a fuse box/rcd box will not neccessarily draw heavy current.
To my shame I once installed an rcd box and did not tighten the factory connected cables and the result was pretty much like the pix Chris has posted. There was no real risk of fire as no flammable materials were nearby but a strong fishy/burny smell alerted the houseowners to the fault.
I put things right but it was very embarrassing for me
Haven't done it since....
Never hurts to check the tightness of all cables with a screwdriver now and again where electricity is concerned and this is not limited to circuit breaker and fuse boxes either.
As for the landlord most landlords will always come out on top but some are actually suffering since this goverment changed the law where those claiming benefits now get cash to pay the landlord rather than previously where landlords were paid direct by Social Security.
This means some tenants now spend their rent money on other things than rent and then often do a runner when arrears are extreme.
Why this Goverment changed the law is quite beyond me...