Undertaking and survey report for tree felling

globetrotterEB

I have been asked to provide undertaking that a tree will be felled once mortgage has been completed. I have also been asked to provide the following from the structural engineer in relation to a survey report:

"the case can proceed subject to the engineer offering Professional Indemnity Insurance to the lender, i.e they can legally rely upon the content of the report for lending purposes. We will require the engineer to confirm this."

I have retrieved a letter on letterhead by the engineer firm confirming the above and signed.

I am just wondering why do they need this when the report itself is an official document and of course it can be legally relied upon?