I can understand why you and your sister had to wait for your elder brother before deciding, the world is harsh these days and no one is to be trusted to talk more of a stranger, and yes seeking advice always helps as no one is an island of knowledge.
Of course. When my brother eventually came back he was glad that we told the man to wait for him. He said he wouldn't be happy if the man had left his car in our house without him seeing him first.