"It was very sad that we didn't see a real contest, but I was really pleased that Kauto was all right.
"I'll go home tonight and look back on a fantastic career. People keep asking me which was his most memorable race but they've all been memorable, he's won so many grade ones."
With the connections of Synchronised celebrating their success in the Gold Cup just a few metres away, Smith and Paul Nicholls, Kauto Star's trainer, were careful not to distract attention from the new champion with an immediate announcement that the 12-year-old had been retired.
Smith made it clear, though, that one of the sport's most outstanding and consistent performers is unlikely to return. "There's not much point in saying he's retired now, he's not seriously injured at all, it's more like a tweak playing golf.
"I'd be 90 per cent sure [that he will be retired], I'll take advice, but someone would have to work very hard to persuade me that you'll see him out again, because I wouldn't want to see a Best Mate situation or a Dawn Run [both Gold Cup winners who were later killed while racing], I don't want anything like that.
"He's given me so much pleasure, he's been a wonderful horse and a great champion. It's sad that we probably won't see him on a track again, but he's in one piece and that's the main thing."
Walsh was in no doubt that he had made the correct decision, and also seemed to accept that the best horse he is ever likely to ride will not race again.
"I drifted further back and further back," Walsh said, "and I was struggling in bad going to the fourth-last the first time round. AP [AP McCoy, riding the eventual winner Synchronised] said to me, 'if I was you, I'd pull him up', and he was right.
"There would have been a hell of an outburst if I turned him over at the third-last and he broke his neck when he had no chance. It wasn't happening, that's horse racing.
"I thought it was [his last race] at Punchestown [last May] when I pulled him up, but it wasn't. I'll leave that decision to Clive Smith and Paul Nicholls. He's been a wonderful horse, the horse of a lifetime, and he owes nobody anything."
Nicholls himself certainly ruled out another run in the Gold Cup when interviewed after the race and Smith said later he would discuss the situation with the trainer next week, but that his "immediate feeling is that it might be enough".
If so, Kauto Star will retire as the winner of 23 of his 40 starts over hurdles and fences, and 19 of his 30 starts over the bigger obstacles, and having banked £2,375,883 ($4,556,684) in stakes for his owner, a record for a National Hunt horse.
Kauto Star's major successes included two Gold Cups and a record five successes in the King George VI Chase at Kempton Park on Boxing Day, while he also won the Betfair Chase at Haydock four times.
In his most successful season of all in 2006-07, he was unbeaten in six starts and also demonstrated his versatility by winning the grade one Tingle Creek Chase at Sandown over the minimum trip of two miles as well as the Gold Cup at Cheltenham over 3 miles.
* Big Buck's once again defied all the doubters to make racing history as the first four-times winner of the Ladbrokes World Hurdle on Friday.
Sent to the front earlier than usual by Ruby Walsh, he fought off every challenger to equal the record for the most consecutive jumps races won, making it 16 from 16 over the past four seasons.
The Irish mare Voler La Vedette gave Big Buck's a bigger scare than most have done when looming up in his slipstream on the run to the final flight, but Walsh's mount met it on a perfect stride and galloped all the way to the line to win by 1 lengths.
In the final minutes before the race, Big Buck's had drifted out to 5-6, having been far shorter in the betting earlier in the day, a series of poor performances from Paul Nicholls-trained runners seemingly leaving punters lacking in confidence.
Relief was evident as Nicholls celebrated the victory. "Apart from the Champion Hurdle it's been a bit of a disaster this week," the trainer told the Guardian. "It wasn't easy to get him here, to bring him back four years winning.
"We have had a problem with a cough as everyone knows and some have been running a bit below-par. I was worried, of course I was.
"Thank God for this horse. He pricks his old ears, keeps galloping and keeps winning. It means a lot to us that everyone is so fond of him and God willing, we'll be back next year to try and win it again."
Nicholls said Big Buck's will now aim to make it 17 and beat Sir Ken's record when heading to the Aintree Grand National meeting next month.
