I agree. There is a distinction between falling into temptation and living in continual sin.Remember though, there is a distinction between falling to temptation, and a life categorized by sin. In your example, if you repent later for it, then you're fine. Repentance means to turn from sin. It's a constant rejection of sin and a fight for walking in righteousness. Everyone is going to stumble, even if someone purposefully chooses to commit a sin. Stumbling doesn't assume it's an accident, it just that... you fell. But if you pick yourself back up and repent for it later, that's what matters. So someone who rejects obedience, is living their life full of sin without repentance.
It's like, if you walked up to your best friend and punched them in the face. How many times you going to punch them without repentance before they walk away from you? Repeated sin draws us away from God (Isaiah 59:2), but repentance and God's grace, brings us back (Joel 2:12-13). It's all about love. If you love God, you'll want to do right by Him, just like if you love your friend, you'd want to do right by them. You may get into fights, but love always tries to repair the relationship as you try to not continually break it.
What I tried to explain from my perspective was about genuine Christains disobeying God, Christians who love God. It is possible for a genuine Christian to disobey God because we all mess up. So it's important to keep our focus on Jesus and not on ourselves or others.