His legs caught the hawthorns. The weight of his camera tipped his shoulders over. In a moment, as the rest of the press surged past oblivious, Mr Ashdown grabbed at the taller cameraman, caught his elbows, and pulled him, shaking a little, to his feet. Then the Liberal Democrat leader gave a small smile and strode on.
Paddy Ashdown is everyone's favourite campaigner. While the other leaders qualify and deny, refuse rows with hecklers and flatter invited audiences, Mr Ashdown suggests the opposite, a ramrod-straight riposte to such timidity. Freed from the likelihood of government, he seizes situations, stakes out definite positions, seeks difficult converts: angry farmers and anti-roads protesters, fishermen and Referendum Party workers.
And when, every now and again, he stops crusading, Mr Ashdown can be quite disarming. On Thursday morning, before his Edinburgh lunge, he was already joking with his press entourage. Today would be a special day: the last school visit; the last patient inquires about book shortages. And the last computer studies classes! The laughter from the reporters, in their tight familiar knot outside Liberal Democrat headquarters, was too loud for contrivance.
Inside, the main receptionist was explaining to a caller, over and over again, the name of their constituency and party candidate. For the next three days, on a national scale, Mr Ashdown plans to do something similar. In person, he will visit 21 seats, buttonholing the possibles, ticking off his points for passers-by, being careful not to get tetchy with the sceptics. His party will "go for victory" - not a governing majority, but, in Mr Ashdown's words, "a massive force of Liberal Democrat MPs" in Westminster.
There is only one problem. What the party and its supporters see as a "massive" election total - 30 MPs, or 40 perhaps, if the Conservatives really collapse - might well be perceived as an irrelevance by everyone else. Without an unlikely hung Parliament, the Liberal Democrats will continue to be as much patronised as they are admired, often by the same people. And Mr Ashdown's brave striding will be mere perpetual motion.
At the school, he seemed to have lost his appetite. Cockshut Hill is in a marginal seat near Birmingham airport, and the visit, at first, had all the uninspiring utility that implies. The pupils lined up at the gates and giggled. Mr Ashdown waved. Under the dead grey sky, the playground tarmac crumbled. He kept his hands in his pockets as he trod the corridors. He met the cricket team. Would he have a bat? "I'll leave batting to the Prime Minister." He asked the boys about class sizes. "They're OK." Should teachers get more money? "No." The conversation did not last long.
Mr Ashdown, it seemed, needed a confrontation: a chat with the bad lads behind the bike sheds perhaps, not this polite procession of teenagers with bowed heads and nothing to argue about. Then he saw the temporary classrooms. They were almost 50 years old, with windows tied shut by wire; finally Mr Ashdown had found inspiration. "Are the roofs leaking? Very hot in the summer? Very cold in the winter?" He fixed on the teacher: "We can invest pounds 500m in the first five years." Mr Ashdown's hands were out of his pockets now. Suddenly, he welcomed physical contact: a drawing to jab a finger at, a stool to put his foot on, safety glasses to wear as he bent over a lathe in the metalwork shop. When he took them off, he threw them across the room to the teacher.
By Edinburgh, Mr Ashdown was full of drama. In front of the statue of Gladstone, as a slash of blue sky opened up behind them, he proclaimed, "My worry is that Britain now sleepwalks into the next century. This country needs to hear the truth." Later, he walked onstage at the Meadowbank Sports Centre to the blast of kettle-drums and trumpets.
If the Liberal Democrat leader could seem commanding, he could also seem to be in command of rather little. The stage set at Meadowbank was grand enough, with slopes of orange and grey as wide as any party's, but the hall held half the number Tony Blair gathers together. This was the speakers' dilemma: the louder they shouted, the more absurd they risked appearing; yet to make the modest noises of a small party was to stay small for good. The members applauded the speeches, very loud.
Mr Ashdown began tensely, fingers rigid as pistol barrels. Steadily he found momentum. It came first, strikingly, against the Government: the Conservatives, he nearly spat, were "drug-addicted to power". Then against both main parties: "the same spending limits, the same tax plans, the same failure to explain how anything will be paid for." Next came the Liberal touchstones: Gladstone and Lloyd George, the need to husband "the gold in kids' heads".
For 20 minutes, Mr Ashdown's speaking became a kind of doing by itself. He could have been lecturing a Labour cabinet meeting, or correcting some future coalition. And this was not mere fantasy: the Liberal Democrats' polls were rising; proportional representation was a possibility under Labour; Mr Blair might need their help. Mr Ashdown, surely, would be too popular to ignore. Then his speech was over; the party workers collected the donations in plastic buckets.