Original post didn't say it dumped fuel
Wasn't quoting the original post, look at 'doors to automatics' post 2 above my previous.
Also agree with 'heathrow directors' post above.
If they'd had a gear problem they were aware of, it's highly unlikely they'd have left it to 100' before deciding to go around
Perhaps they had to go around for traffic on the runway, and subsequently suffered a hydraulic failure?
As to the proximity of the other aircraft on the G/A, it's nigh on impossible as a passenger to judge the proximity of other aircraft, especially when one or both aircraft are turning.