I would doubt that this is a statement on his part. Puppies will go whenever they have the urge and it takes a while for them to learn control. The best thing you can do is:
1. Take him out (not let him out) on a regular schedule and PRAISE him when he pees or poops outdoors - make a really big deal out of it.
2. Make it hard for him to fail. Do not leave him alone in the house out of your sight. If you cannot be watching him, crate him. I would never leave a puppy on his own in the house while out in the garden - you are asking not only for him to have an accident but to get into any number of dangers in your house. It is safer to crate him.
3. When you can watch him do so - even if it requires you to keep him on a leash near you indoors. Immediate intervention when he does have an accident - scooping him up and bringing him right outside - is the only way he will learn where he should and should not be going.
4. Thoroughly clean the area where he has had the accident with a enzyme neutralizer like Natures Miracle. You need to make the urine odor undetectable to a dogs nose.
Sharon, Blaise and Diesel.