With all due respect to the poster above, there is no point in comparing the incident you were involved with and this incident. I was there and can say that even though I never saw smoke the impression was something was burning. The smell got considerably worse over a 10 min period before it was decided to return to the stand. During this time passengers were increasingly finding it difficult to breathe.
If the plane had reached the jetway and the front door was opened can you imagine the carnage if people had then spotted smoke! No point in announcing over the PA "don't worry chaps, it's just an AC problem and there is nothing to be concerned about". That may be the SOP but in a real life crisis people's survival instincts kick in. Far better to get people off in the chutes than attempt to put 300 panicking passengers through 1 door at the front.