I'm not jumping on any particular bandwagon, but here's one angle. If - IF - people who heard and/or saw a plane near the explosion site were correct, and my theory above of a plane dropping/shooting something on the leaked gas to cause an explosion is correct, the plane could be a small plane that didn't come from or land at that airport. Like a crop duster or other small plane. It looks like an agricultural area from pictures. I live in a rural area and there are more that a few really small little airports. Real small.
Not saying I believe any scenario more than another one. But I agree that for authorities to state, imply or say that an event is not terrorism, when it's too early to know with absolute assurance, is not reassuring.
It wouldn't even have to have been an airport. A small ultra-light or similar type plane could take off from any relatively flat strip of land. Heck, they could have even taken off on a flat stretch of roadway. I'm sure there are plenty of smaller such roads and areas in more isolated regions of the country.
"It looks like an agricultural area from pictures. I live in a rural area and there are more that a few really small little airports. Real small."
Hmm, well rural has to be placed in context. Hemel Hempstead is a reasonable size town, Watford is about 6 miles South which pretty much merges into the North of London and Luton is 10 miles to the North. There's 3 International airports (London Heathrow, London Luton and London Stanstead) within about a 30 mile radius.
I don't think there's anywhere in the South East of England that could be remotely called 'rural' in the same sense as parts of the US could be.