Guess what. The 30-seconds silence at the start of the 2013 Virgin London Marathon, in honour of those affected by the Boston Marathon bombing was, according to the BBC commentator, "impeccably observed".

As if it would ever have been otherwise.

And so the stilled river of human enterprise reflected in the April sunshine, each runner bearing a black ribbon of remembrance for those killed or injured in New England. The emotional level of the London Marathon – always high – rose still higher.

Thankfully the only shocks on the day were restricted to what happened in the racing, where Ethiopia's Tsegaye Kebede produced one of the most extraordinary finishes in the event's history to snatch victory from Kenya's Emmanuel Mutai and where the chances of the women's Olympic champion, Kebede's fellow Ethiopian Tiki Gelana, were effectively ended when she collided heavily with the wheelchair bearing Canada's Josh Cassidy, the 2010 London winner, as they converged on a drinks station.

A shaken Gelana picked herself up and re-joined the leading group, but before long she was reduced to the status of a jogger by the effects of the impact. Cassidy, too, had his race effectively undermined - not to mention $2,000 (£1,300/€1,500) worth of wheels. "Who is going to pay for those?" he asked, adding that the organisers and the BBC needed to re-schedule the starts so that the possibility of such unhappy convergences was avoided in future.

Runners wearing black ribbons observe the 30 seconds silence before the London Marathon to mark the Boston Marathon bombings

The eventual winner of the men's wheelchair race, Kurt Fearnley, was succinct in his post-race conference when asked whether the wheelchair racing should be should get underway first to ensure clear water between themselves and other runners. "I've thought it for years, mate," replied Fearnley, who took possession of the title home racer David Weir had coveted as he sought a record seventh London triumph.

Commentators hazarded that a record crowd had gathered to affirm the continuing sanity of this race - and the human race. Judging by the depth of the spectators along the route, concerns about safety in the wake of the Boston outrage had not induced too many people to stay at home.

Certainly it seems the athletes never wavered. Tatyana McFadden, who completed a wheelchair double here following her victory in Boston, insisted afterwards: "Boston was a tragedy, but you saw how the community came together. I knew we were going to get support from London and all round the world. There was never a doubt that I would race - I was going to race for those back in Boston. I definitely dedicate this win to those in Boston and for those trying hard to start healing the heartbreak.

"I wasn't too worried about security because we had the Paralympic Games here last summer. Today was about running for Boston, and I can't thank all the supporters who turned up enough."

Fearnley concurred. "I had no thought of not coming here," he said. "It's a horrible situation, but fear can be a pretty debilitating thing. Letting that in there and letting it affect your life is not something I wanted. As soon as we woke up that next day after Boston,  I don't think any of us thought about not racing here."

Priscah Jeptoo, Kenya's winner of the women's race, commented: "The security was so good. There was no fear for us or all the people who were cheering us."

Sniffer dogs in action before the start of the Virgin London Marathon

Among those who stuck to their plans to attend was Prince Harry, who was presenting the medals. Asked to comment on the size of the crowd, he replied: "It's typically British. People have been saying they haven't seen a crowd like this on the route for many years, which is remarkable. It's never going to get anyone down here.

"I was always going to be here. There was never an option. No one has changed any plans. Nothing has changed – the London Marathon was always going to be really well run. It always is."

But who can really know what combination of factors caused this year's spectators to congregate? Perhaps the presence in the field of the home double Olympic champion Mo Farah - for just under half the race, as per programme - prompted additional attendees.

Mo Farah (left) strides out as the men set a world record pace in the first half of the 2013 Virgin London Marathon

Farah acknowledged being taken aback by some of the criticism he had received for running half a race this year as part of a package said to be worth £450,000 ($685,000/€525,000) which will see him make his full debut here in 2014.  Michael Johnson, the retired Olympic 200 and 400 metres champion, wrote in a newspaper column that the Briton was "risking ruining his reputation" by doing so, as it "looks like it is all about the money".

Asked about this following his effort today, Farah responded: "I can't believe what some people think. But sometimes you have got to do what's best for you."

Two other reflections on the day's events came from the fabled north-east runners who were commentating on proceedings for the BBC - Brendan Foster and Steve Cram.

"This is like London's response to what happened in Boston last week," said Foster. "And the response is - you can't stop us doing what we want to do."

Cram commented: "If you want to break the human spirit, marathoners are the wrong group to pick on."

You could only agree with him – although perhaps "marathoners" could have been extended to include marathon followers...

Mike Rowbottom, one of Britain's most talented sportswriters, covered the London 2012 Olympics and Paralympics as chief feature writer for insidethegames, having covered the previous five summer Games, and four winter Games, for The Independent. He has worked for the Daily Mail, The Times, The Observer, The Sunday Correspondent and The Guardian. To follow him on Twitter click here.