It may well be the case. I did not suspect bore fouling at the time, but what happened is consistent with it. The only way to disprove it would be to let the barrel cool off, and then try again. I did not, in part because we had a hot muggy summer, and I was ready to leave the range within an hour.
If it was fouling undetected, I think looking back at it, that's great. Clears the way for another Tikka. I like the action, but I still don't regret letting that one go, because at almost 9 lbs and 24"bbl it was longer and heavier than I needed.
Thank you Picher and everyone who opined. This has been a great forum, I am leaving it with a probable answer that I didn't think of myself.