What more will you lie about in the future if you feel a need to lie about more than 8 hours of instruction.
If he did not actually give 8 hours of instruction, then he would not be lying!
What is the definition of instruction? On a flight with a qualified pilot at the controls am I allowed to take my instructor's hat for a portion of the flight, or am I required to instruct, and log it as such, just by my presence? What if I elect to take a litte siesta during the cruise phase? Do I have to log that as instruction?
Who cares about what the inspector will or will not do. The fact of the matter is that if you break the rules it does not matter wether you knew about it or not. Intentional or unintentional again you still messed up.
It may take some interpretation, but if he honestly did not instruct the entire flight, then he can honestly log less than the 8.5 and not be lying about it. Otherwise, he's running towards the FSDO covered with gasoline and flicking a BIC lighter.
You obviously have never had to deal with an over-zealous, FAA inspector, looking to take someone down. Most are not this way, but a few are. Those are the ones that we must protect ourselves against. I've been there and fortunately for me I was working for a company with an attorney that cut him off at the pass.
Here's the kicker. They do not play on a level playing field. They do not play fair. They do not play straight. They play by their own set of rules. They are unrealistic. They will bend and twist things to their advantage. You might even be guilty if proven innocent. (Sounds like I'm talking about the IRS!) Go talk to any reputable charter operator and ask them about it.
This type of tiny little discrepency means absolutely nothing....except to some inspector with hard on. Nobody was wronged or harmed. Nobody did anythhing unsafe. Don't give the FAA, or anyone for that matter, the rope.
I am not advocating lying. It is all about interpretation because that is where we are with that organization. Let me say it again. Do not give them the rope, ever, because they will use it in a heartbeat! Do not give them ANY rope. They will use the wrong rope, on the wrong tree, if it suits them.
As an old aviation salt once said, "When dealing with the FAA, even if you are knee deep in water, NEVER admit your feet are wet"!
Don't sweat it. Make the correction to what you actually instructed and forget about it!