Sounds like the website you use for for the WHOIS query only allows a certain number of queries within a certain time frame in order to protect their service from overload. It doesn't mean someone is trying to register.
I'm not an expert, but I have heard that domain re-seller businesses can be very quick in snapping up expired domains. Rather than just waiting for it to become available, I would look for a way to guarantee that you'll get it, e.g. offer money to the ex-friend to transfer the domain to you. There may be other tools, e.g. back-ordering, but I haven't got enough insight myself to advice.