As a specific example, in the FAQ section I found the question "For how long are the documents kept?" with the response "Yes, all signed documents are stored on our secure server for three years to ensure their integrity." A native English speaker would more likely say something like, "How long are documents stored?" "All signed documents are stored on our secure servers for three years..." Similarly, some sentences in the Legality section were a little confusing to read for the same reasons.
Again, not trying to start a flame war over grammar. But, as a potential customer to a company that would be handling my legal contracts, I'd want communication to be as clear as possible.