CAS - if a neighbour damaged your pipes and flooded your house and offered to pop round with a mop and some gaffer tape to fix it, would you just accept that?
or would you want to call in a professional plumber to do it properly?
offering to 'put it right' himself is not good enough - as hes clearly not a professional - and actually seems a bit of an idiot and likely to cause more harm than good - what pro would have randomly hammered on a piece of wood, with no thought to the consequences?
a pro would have known better.
you have every right to have the damage rectified by a qualified person...