All i can say with definitive authority is,
first, it's unlikely to be a ban based off automated rotation routines.
and second, Almost anything that HB does could "give the game away" if you speculate wildly.
Even after playing devil's advocate, there's no real evidence of Tyrael or frame lock bots being anything but efficient.
speculatively, i don't know. there could be a throttle or flood detection effect, or some kind of automated trigger when you use 4 spells in the correct timed sequence, like an evil "simon says"
but all of that is very unlikely, due to the extensive number of people using routines all day, every day, for years. It's far more likely to be "characteristics of play" from addons, plugins, bots and QB's that are noted by a player or GM,
or the dread LCP...
or ... anything.
If it's an automatic system flagging combat usage, then a lot of others like PQR and other routines, would also be in the firing line. Really, anything that is done in bulk, any kind of targeting or positional code would also be suspect, i.e. totems or aoe effects, moving out of fire, strafing code, unstucks, things that are signatures, stand out if you're looking for it.
Any ban most likely requires human intervention and review, which can also lead to false positives, and false negatives. The compensating argument is, if you're the top of your field, people will copy your moves and idiosyncratic behavior, use the same macros, strafe the same way, etc.
So, not to dismiss this entirely, there just could be something that is leaking through, and, your suspicions might be confirmed one day if there's something to correlate.
hence the ban reports.
The odds are, it's more than likely a flagged issue, 6-12 months ago, and the backlog is that immense that it takes time to go through a backlog of records, notes and parse them through the ban-0-matic(tm) process,
this would be a system where a server might get 20,000 spam flags a day from spam-flagging-addon users, because someone said "i need 50g to buy a mount plz some1 help" in trade chat, the same system is most likely buried in players blaming bots for PvP losses, undercutting auctions, everything but the reason illustrated in the complaint, it all has to be reported, filed, sorted, and flagged by someone and investigated, and you never really know.