Corporate employee brought action to recover for alleged breach of terms of employment agreement, and his employer defended based on broadly worded release provision included in the unexecuted subscription agreement pursuant to which employee allegedly received his stock in corporation. The Sixth Circuit Court of Appeals held that genuine issues of material fact as to how corporate employee received his stock in corporation, whether pursuant to terms of subscription agreement which he subsequently refused to execute or in partial compensation for his services, precluded summary judgment for employer, on estoppel theory, based on broadly worded release provision included in the subscription agreement.