James,
Leaving aside the consequences to you, and I think you are understating them significantly - but that's for another thread.
Blowing the slides would likely lead to panic on the aircraft, leading to an unsupervised exodus from the aircraft. Minor injuries would occur, scrapes bruises, broken arms, ankles, legs. Serious injuries are also possible. With 300 plus passengers milling around the ramp the airport would likely freeze all aircraft movements in the vicinity - and likely the same with ground movements until all passengers are accounted for. Other flights both inbound and outbound would begin pulling delays, compounding the existing problem.
And since the bottles and slides would have to be replaced (as many as 10 sets) you are likely adding many more hours before the flight could be completed
Even if it was only one door you would be making the situation much worse for everybody else.
From what I've seen in the press and here I've seen nothing that suggests that the passengers will maltreated. Since there are no complaints about heat, food, toilets, etc. I have to assume that AI treated their customers well. OK, so everyone would be bored to tears sitting in a tube for hours on end, but that's what air travel is all about, n'est pas ?
This problem was not AI's fault, and it appears they did reasonably well given the circumstances. This situation will be costing them a bundle, all because of the crap infrastructure at Heathrow that can't handle a little fog.