His effort was all the more remarkable as his own stablemate Escapee set a searing pace that saw eventual winner Stig break the national mile record by clocking 1:55.2.
Purdon said the performance left him stunned. "He has never given any indication of doing anything like that," he told the Herald.
"He will occasionally pace for a few strides when he starts jogging at home but he has never switched into a pace at full speed and definitely not in a race or workout.
"With his all-trotting breeding it makes it even stranger."
Purdon said I Can Doosit didn't feel great in the warm up and had he not restrained him in the final stages of the score-up he would have rolled into a gallop.
Purdon said a vet examination after the race suggested I Can Doosit was jarred up, which will be worked on this week.
That should have him back to his best for the $80,000 National Trot on a stellar day of racing at Alexandra Park next Monday.
"We can work on it and I think he will be fine, but it was a very strange race."
There were two consolations for Purdon - the brave performance of Escapee in finishing second and the massive performance I Can Doosit put up after his early problems.
"It just goes to show you what a great horse he is, to trot back into the race at that speed after that."
That still wouldn't have greatly amused the punter who put $14,000 on at $1.25 fixed odds.
I Can Doosit's loss will at least open a window of hope for the trainers of the other superstars of trotting, showing the great horse is not invincible in the $1 million worth of major trotting races that lie ahead this season.
Almost overlooked in the I Can Doosit carnage was the performance of Stig to break the record, capping him own incredible comeback.
The 10-year-old was retired three years ago and spent two years in the wilderness before trainer Paul Nairn was convinced to put him back into work.
That he could trot 1:55.2 at a stage of his career when his old, battle-scarred legs don't possess the speed they once did reminds us what a special animal he is.
It also increases his chances of finally making it to Australia for the rich races coming up there as he is the only trotter who has a motor to match I Can Doosit.