Peter Frimberley wrote:

(OP snipped)

I'd be dropping a strongly worded email to TfL with the bus route
number and journey plate number. The *very least* the driver should
have done is made an announcement at the last stop that was on the
normal route, that the bus was about to divert and passengers would
not be able to get off on the diversion. All the bendy buses have the
facility for the driver to make an amplified announcement.

If I had been abducted in the way you describe with no warning
announcement, the emergency exit button would definitely have been
tested at the next traffic lights. I don't believe it can be disabled
but if it was just pull the door anyway or get some bloke to do it,
they're not that strongly closed that you cannot force them open.

Bear in mind that the bus driver is responsible in part for your safety
whilst you're on their bus - they are not purposefully acting in a
malicious manner. But yes I quite agree that an announcement before the
diversion should be the standard modus operandi.

Emerency exit buttons cannot be disabled, but as a poster has pointed
out elsewhere they can be counter-acted by the driver pressing and
holding the close button. I've seen shady characters use them on
multiple occasions to get off the bus. One should bear in mind that
using the emergency exit button will be against the rules so you could
conceivably end up in trouble for using it in a non-emergency.

In addidition there is a potential safety issue of whether you, or more
importantly anyone else (who're either following you out or are just in
the vicinity of the door and fall out) suffers an injury, either
because the bus is moving, or nearby traffic is moving. In a situation
where someone is feeling angry and self-righteous they might not
necessarily take proper account of the whole situation. I have visions
of fellow passengers following a seemingly respectable gentleman or
lady (the respectability seemingly adding legitimacy to the use of the
emergency exit button) and ending up getting run over by a motorbike.