i've been doing allot of low level pvp in the burg and the parish through my dragon eye. i too have been summoned by players who had not acquired any scales yet (confirmed through messaging). i play on the PS3 so it might be specific to the console?
when i invade as a dragon at low levels, i usually drop an item in trade when i know i'm facing a noob with base level gear. i try to leave chunks, twinkling, demon titanite or humanity when i have the available. i might leave a hard to get weapon like the balder swag sword, if i have one, but i never leave upgraded weapons though. i figure its fair if i'm reasonably sure that i could dispatch them quickly.
i also think that it's fun to toy with the noobs on occasion, using base gear and kicking them around without doing any actual harm to them. i might get behind them and kick them in the butt instead of backstabbing them for example. this one time, i got summoned by host who hadn't even figured out the lock on system yet. i punched him around with fists until he eventually killed me. then he summoned me again almost right away. it was awesome because we sparred for a quite a few matches and he kept giving me the scales he won after i let him beat me several times. the best part was that he was noticeably better after each match. i showed him parries and backstabs and he caught on rather quickly. it was a nice experience.