It's probably much more boring. The choice was likely between leaving the whole water bottle and its contents in a bin of forbidden/discarded items, going home and missing the flight, or chugging it, or arranging a courier for said bottle.

Probably the act of defiance of pouring the contents onto the floor where there was no drain was implied to be disruptive and would have lead to harsher sanction for no reasonable payoff.

I doubt very much immigration told you to drink a water. Hell lost of the time you don’t even talk to them as they’re e-gates and it’s remote.

Security might have done, this is nothing to do with the border farce.

> Heathrow has well publicised cases (and is not unusual in this)

Share with us your best source for this.

Heathrow is a fucking miserable place with spiteful staff and it would not surprise me one bit if someone decided to fuck with a traveller this way. I saw a girl running to catch a bus to another terminal for a connecting flight, and the guy controller her made an enormous stink about her "breathing on me". She was polite and apologetic but she got pulled aside and made to wait for everyone else to get through, got sternly chastised before being allowed to continue (whereupon she missed the connecting bus and presumably her flight). Same trip I saw them them shouting and swearing at disabled travellers who needed wheelchairs. Every other member of staff in the airport was stood around fucking with their phones and seemed furious whenever they had to do their job.

Horrible airport, avoid at all costs.

>Heathrow has well publicised cases

People attempting to enter illegally, not for failing to down drinks like it's a frat house...