I don't understand how Bots, scripts, or tools can bypass the forum's backend to tracking user's total logged-in time.
It's isn't something on the front-end that can be manipulated easily by something like inspect-elements and making the mamas proud of those who do it.
IMO someone running a particular stats website might be accessing the forum more frequently than once per second on a long term basis and these are alts of this person to collect this data.