Maybe this is the "evacuation" which raises the important questions of how and when should we evacuate. What is clear is that our current policies are criminally lacking. For a start, I don't think we shouldn't be doing "precautionary evacuations." In general, because most aircraft are not fitted with integral air stairs, we should either do a full evacuation or nothing at all. This is because we are not trained to do "half evacuations". Our training is "evacuate" and that's it, shooting from the hip in critical situations like this doesn't work. I'll also throw another one in here as well. If you have a "smoke" problem, you should consider where you will be parked. Airport staff should not connect an airbridge to an aircraft they suspect of having a problem such as this. And if they did, the door to the terminal should be locked. Which would generate additional problems for PAX emerging from a sick aircraft.
We should also question the value of evacuation advice from airport fire crews. These poor sods play table tennis and volley ball day after day and every new and again put out yet another practice fire. They rarely get up close and personal with aircraft; partly because there are not enough of them on shift to allow them to wonder around the apron learning about aircraft from engineers - if the security Gestapo would allow such activity in the first place. Therefore, I'll suggest they will play "safe" and get you to evacuate.
As for this event, we have some interesting questions such as why were the flaps up and why were the over wing exits not used? Why did they evacuate? I wasn't there so I won't judge the crew, but it would be nice to know. Also Bloggs and LSM throw in their "right on the money" comments as well. Combine this with the previous Jet2 (please, I'm not having a go at Jet2, it's just that it was them) evacuation at GLA and we might be able to come up with a better way of dealing with not only "real" evacuations but also those occasions where something is not right, but where an evacuation is not the most prudent course of action.