I don't think piemans ban could have been because of him using the bot, because he'd not used more than 4 hours in total. Then the ban was at least 2 weeks after his last communication with the RID server. Sex used the bot more than 12 hours almost every session, and over 20 hours on multiple occasions, the top of the leaderboard in terms of hours used but this is the only ban there has been since 22nd May, over a month ago, out of 300+ who've used the bot in that time. It also wasn't a week later it was 3 days after his last botting session. Any delay was probably due to Jagex snapshot and ban appeal team having a mountain of other work to go through between his activity first being flagged as suspicious, but unfortunately due to the extreme nature of his use, it was probably an open and shut case.
It seems they cannot detect the bot by any conventional means, but they will ALWAYS know exactly how long you spend logged into RS and at the MTA. Don't bot for more than a player could realistically play, so about 8 hours a day is a nice figure.
The new MTA bot will make the J-Mod's job a lot harder, a bit more has been mentioned in a previous post but if pulled off correctly, the bot's activity/behaviour will no longer be something able to be analysed, combine this with all best attributes from the current bot, a few bug fixes and I'm guessing once the new program is out it will be the safest time to bot we've ever had. It is ambitious, as ever, so expect possible delays, but V4 of the MTA bot should be here by 9th July.
In the meantime, as long as you use V3 sensibly the statistics show the chances of being banned are practically zero, certainly this has been the case for over a month with V3.03.