I applied for HSMP on 13 March. Instead of posting my documents from India I sent the documents through my friend and he posted from UK is this a mistake?

I made the application for HSMP when I was in India. Since my friend was travelling to UK, I thought it would be safer for me to send the documents through him and get the same posted with in UK, rather posting it from India. Now I have received a letter and my documents stating that they will not b...