IIRC i don’t think you can patent single techniques that have been out in the open before. What the author could do is patent the bundle of tecnhiques with the process attached (custom workflow), which basically means the product.
If it’s like this you should have no problems using the same technique, but if you code a plugin with the exact same workflow and sell it you’re gonna infringe the patent.
Other than that it’s the grey area of law. nothing anyone can do about that.