Canadian show jumping team to miss Olympics due to a coca tea

I am all for the recent clampdown on illicit substances in sport, but occasionally you can't help but feel that the powers-that-be are being a little over-zealous.
A case in point is the rather harsh decision against the Canadian equestrian show jumping team, based on a positive drug test at the PanAm Games in Lima this last summer. One of the team of four, 26-year old Nicole Walker, tested positive for cocaine after drinking a coca tea in a Lima hotel. Coca is a widely-available and perfectly legal tea in Peru, and while it is techically made from the same leaves that are used to manufacture cocaine, the effects of coca tea are very mild. To add insult to injury, Ms. Walker, a big tea drinker, apparently intended to drink green tea, but the coca and green teas come in a very similar packages.
The worst part is that the whole team of four (and, arguably four horses!) will be disqualified from next year's Tokyo Olympics as part of this decision, which seems a bit ridiculous. The Canadian team placed fourth in the PanAm Games, and would be considered as medal contenders in Tokyo. Shades of 1995, when a four-person Canadian rowing team lost their PanAm gold medal because one member took an over-the-counter cold remedy!
I know we need strict rules against drugs because there are s lot of people out there abusing them (looking at you, Russia). But surely testing is sophisticated enough to distinguish between performance-enhancing drugs and coca tea or Robitussin! And why ban the whole team for the dubious sins or misjudgements of one member?
The team will appeal the ruling, and feel that they have a good case to make. Don't hold your breath, though, and definitely don't take any Benedryl.