I've followed this thread for a few days now and have resisted the temptation to comment, mainly as a result of my being a lowly traction & rolling stock engineer, rather than an operator.
However, there are some T & RS design issues involved in this as well as ops issues.
Firstly, the issue of hopper windows that provide emergency ventilation. As most people know, air con works best in a "sealed" space, which is why hoppers that can be opened "willy-nilly" are not provided. However, it is simple common sense to provide some hoppers that are under train crew control, and this is usually done with locks that can be operated with a carriage key.
For commuter trains and DOO trains, this is not a practical proposition so it makes sense to fit these trains with hoppers that unlock remotely. I say unlock, because a latch to retain the window in the closed position would still be provided, so that the windows don't simply drop open when the remote control is operated (this was covered in an earlier posting). The remote control should either be an electro-magnet or a solenoid (shoot-bolt), that de-energises on activation, so that in the event of a power failure (and loss of air con) it operates automatically, enabling passengers to open the windows, presumably after being prompted to do so by the driver over the PA.
Regarding manual door release and TIS, the T & RS engineer has little influence on the functionality, as the working practice is set in the Rule Book (I don't intend to delve there!).
From here on in this post, I'm straying into operational matters and I'm prepared to be shot down by the operators. Maybe it's me, but surely, in the time it took for this incident to unfold, it should have been possible for somebody to show some leadership, predict that passengers would de-camp, formulate a plan and de-train under operator supervision, leading the passengers to a place of safety. On is it just me oversimplifying what was probably a very fraught and stressful incident?
I'm sure that whatever the outcome of the investigation, FCC will plan so that this doesn't recur.