I've been working for a company as a contractor for several months. While working for this company, I created some seriously sensitive IP. This is IP that is nigh on patentable.
My employment with this company is based on a handshake deal. There was no employment contract, NDA, or even invoices for the paychecks I've received. I had even suggested signing an NDA when I started working, but the owner refused. The IP is software that I haven't even been released to the company (it's SaaS that I both author and run).
I've become disillusioned with the CEO of the company who is obviously making terrible choices for the company, while underpaying and overworking employees to an extreme and also treating customers poorly and overcharging.
I believe I can do a better job running the company, so I've decided to quit and start my own version. I am already well into the black, but I've used the old company's IP (only IP I've generated) and sales leads (picking up their lost, frustrated clients).
I have no intentions to deny the company access to this IP, but I do intend to use it fully.
Are there any implications to this, both ethical and legal? Assuming I've had no written interactions via e-mail saying that I've been paid to develop IP for this company.