I am an Architect in California working on a California commercial project ($20 million valuation). We are four weeks PRIOR to Substantial Completion date and General Contractor is pressuring me to release retention on Demolition and Excavation subcontracts. He is saying this is 'standard practice'. I am firmly objecting for following reasons: 1. subcontract scopes are not even 100% complete 2. punch list has not even been issued yet Does G.C. have any legal grounds for pushing me into releasing retention?