There is nothing unethical about the fees you describe and in fact fairly normal here in Southern California. As to filing a lawsuit to obtain a higher percentage, it would not be correct if that was the only reason, but there may be other reasons that are not immediately obvious - e.g. as a negotiating tactic to show the other side one is serious, to protect the statute of limitations, including any shorter periods established by contract. The retainer agreement your friend entered must be in writing and must disclose that the percentages are subject to negotiation, but if that's what your friend negotiated or agreed to, there is nothing unethical on its face.
The above is general legal and business analysis. It is not "legal advise" but analysis, and different lawyers may analyse this matter differently, especially if there are additional facts not reflected in the question. I am not your attorney until retained by a written retainer agreement signed by both of us. I am only licensed in California. See also avvo.com terms and conditions item 9, incorporated as if it was reprinted here.
Some lawyers get their costs first and then split the rest. This is how I do it. Others take their fee before they remove costs. It depends on what the fee agreement says.
A lawsuit will not be filed unnecessarily. The lawyer wants to resolve the case as favorably and quickly to you as the client as possible. Good luck.
The attorney and your friend entered a contract for legal services, so that document will control how the recovery is split. The courts allow parties to negotiate for many different terms in these sorts of contracts. The terms you mention above are not universal, but they are not that unusual either.
It doesn't sound like the attorney did anything wrong.
Legal Disclaimer: Mr. Bowen is licensed to practice law in California. The response herein is not legal advice and does not create an attorney/client relationship. The response is intended as legal education and to provide general information about the matter within the question. You may contact the writer with these links: firstname.lastname@example.org http://www.bowenlegal.com