Only my personal opinion. Seems very odd that they would sign an NDA. The deal is that when two companies meet it is more common that both companies will say that they do not want to exchange confidential information. There might be exceptions to that... but generally one should always say NO. Then only consider if there is a very good reason.
Other thing I would say is that NDAs have a scope. So you cannot really evaluate the NDA unless you read the document and know the scope. Could have been very limited scope.