Correct they were stuck down for the lie not for witholding what belonged to God anyway.
In the Christian walk through life, being open and thus honest with the Holy Spirit is essential to the spiritual health and well-being of the Christian individual and thus their family, and acquaintences. If we lie within our self, thus lie to the Holy PSirit within us Who is our guide when we are walking uprightly, there is no conscience to hold us back from further immorality. Had Peter allowed the lying to go unaddressed and God not struck Anaias down as a frightful example, the body of believers would have sunken into all manner of unChristian behavior very quickly, as each did what was right in their own heart rather th because the heart of man is desperately wicked, not follwing the leadership of His Spirit within. This is how a Jimmy Swaggert or other minister goes so far astray.