http://i.imgur.com/ZM2ztiu.jpg

Apparently the duct tape failed sometime on the inbound flight.

Edit: imgur link too large.

I'm not sure how you can decry AC's quality based on a passenger oxygen unit electric door latch being on MEL?

A quick look at my type's MEL list says this unit can be put on MEL with some restrictions//door is secured closed (adhesive tape may be used)//oxygen system operates normally//flight remains below FL300//no more than two consecutive banks of seats have an inop opening feature//non-adhesive 'handle' is made, so if necessary door can be pulled open//occupants briefed on oxygen mask access and procedures.

The flight can carry on safely until reaching a maintenance base with the appropriate part. Clearly, the adhesive tape didn't do the trick and came off, which doesn't look nice, but the oxygen unit would still function properly.

Would you rather the flight cancel awaiting one of these electric door latches?

An MEL keeps the airline running safely, until maintenance can find parts and have their time with the bird.

Aircraft overnighted at Pearson, where one would think they'd have parts and mechanics, and AC killed the row of seats on an already oversold flight because of it.

I'm not suggesting it's unsafe, just poorly managed.

Could be a good way to get some compensation out of AC and/or better IRROPS rerouting.

There are over 200 aircraft maintenance engineers on the overnight shift for AC in YYZ. They work all night on the aircraft. Trust me, if the part was in stock, it would have been fixed. Aircraft have millions and millions of parts, and the fleet is diverse.