From: Bebe
Upon my last look at client code, they have the ability to track mouse movments and clicks from everybody, but you have to understand that that is a lot of data to collect, store, analyze and do whatever with. So I have come to the conclusion that they only trigger such such tracking methods when you are "flagged", which can occur for a number of reasons.
If you auto smart and not abuse macroing systems then there is no reason for you to ever be "flagged"
This is the opinion that I hold as well, mostly because I took the time to read a leak of the pmod forums that was made available on sythe.
One of the jagex moderators essentially revealed that the macro detection system is linked to the report abuse system – remain unreported and the majority of their macro detection mechanisms remain inactive.
At the end of the day nobody can prove or disprove this theory.
However, when all is said and done, Jagex only has several hundred employees, so it's reasonable to believe that most player behaviour isn't subject to scrutiny.
Realistically, you shouldn't be getting caught unless your methodology is so severely flawed that you're throwing up red flags for other players to report you on. This includes things like impossibly long amounts of time spent in-game, or absence of reasonable reactions to things occurring in the game (ie, you run a bot that hunts red chins, someone else suspects you're botting and starts placing their traps where yours are, and your script fails to either move on/change worlds/tell the other player to buzz off).
Occasional conversation also lends itself to legitimising the account in the eyes of other players.
It's widely believed that bots either can't, or simply don't, talk… If you were to say something outlandish such as 'Well personally I like my lamb chops medium rare' and then follow up with something like 'Oops, that was meant to go to clan chat' then that can potentially deter surrounding players from reporting you.
tl;dr: Macro detection system would produce too much data to be useful to Jagex if it was activated for everyone by default and is thus triggered by the report abuse system – so avoid being reported.