I'd wager big money that misfire was the result of contaminated power.
Primers are nearly impossible to contaminate, (ask the manufacturers.) Don't worry about them.
There are enough replies here to help you determine what it "might" have been but "greasy powder" is a top suspect.
Was it only ONE cartridge or several?...(an important question.)
If you never get a repeat performance you may never know but an examination of preparations and techniques used will probably prevent a recurrence without solving the mystery.
You already [probably] solved the recurrence by making sure your cases are DRY.
Be very sure there is no lube getting into your cases while resizing, (an easy thing to happen if a lot of lube gets used or allowed to accumulate in the die.)
I had what you describe about 15 years ago with a small batch of 45/70.
After 2 shots in a row of what you describe I stopped, pulled the bullets and could plainly see that the powder was contaminated. The rest of that story is moot. I cleaned up my act and never saw it again.
"Trust in The Lord and keep your powder DRY!"