I would imagine that Ferrari are used to that type of response, given the exuberant wealth their customers usually enjoy. I'd have expected the dealer to have explained why the repair does not fall within scope of the warranty, and i would also expect there to be an appropriate clause excluding the part.
If the warranty however is incumbent of all mechanical parts then it would be difficult to wriggle out of.
This a lot more wriggle room in this kind of “legal discussion” than simply being a black and white, will a judge say they are liable, situation.
Legal challenges have to be defended, investigated and submissions made, there is a cost to this (here the wealth of the protagonist can mean they will just want to prove a point and will spend).
The retaining a solicitor is a statement of intent, and can indicate the loss of a lucrative commercial relationship. In the case Matt noted above, they lost the customer.
Not all contracts are well written (a lot aren’t) so there can be a lot of ground to cover in terms of what really is and isn’t included.
I find T&Cs are just a starting point for further negotiation, it’s just that some parties need more persuasion to start negotiating than others.