The 25-year-old Blairgowrie player, who had started the final day in the Czech Republic in a five-way tie for the lead, covered the first eight holes in three-under to be leading on his own.
But, after running up a double-bogey 7 at the ninth, Neil had to settle for a closing 72 to finish in joint-ninth on 11-under, five shots behind winner Marcel Schneider from Germany.
“The first eight just seemed very easy,” said the Scot. “Three-under through eight, I felt very good and nine I can’t even explain what happened.
“My bad shot has been a pull this week and I just hit the worst block ever with an 8-iron.
“I’d got a little bit lucky off the drive and, while you don’t want to think it’s your week, but I did think that was a good bit of luck and things were looking up for me.
“What followed though was a bit of a calamity of errors, to be honest, but these things happen and you’ve got to move on from them.
“I think that kind of halted progress as I never really got going on the back nine.”
Despite being unable to join Craig Howie in delivering a Scottish success on the second-tier circuit this season, it was easily Neil’s best performance of the current campaign.
“It was still great to be in that final group. It’s been four years since that was the case and it’s nice to be in that situation,” he added.
“I’ll go away from this and speak to my coach and a few other people and try and learn from the day - that’s the most important thing.”
Schneider birdied the last three holes to secure a one-stroke victory and that coveted spot in the season’s final major at Royal St George’s.
“I heard about The Open spot on Friday during the round, I hadn’t thought about that before,” he said. “It feels even more superb now.”