Sorry about your flat.
Full marks for self-sufficiency to get the wheel out and dismount it in the carpark, you don't see that much anymore.
I would have pulled the front wheel, used my tie downs to anchor the centrestand to the re-inserted front axle and then rocked th bike forward and taken the rear out downwards. I realize that time wise it's six of one and a half dozen of the other, but I reckon pulling the LHS pannier mount off is more fiddly.
You may have spotted a few weeks back when I announced I was going tubeless on the rear snowflake (the front K100 rim is already designed to be tubeless).
Well my grand plans unravelled when I could not get an airtight bead seal on the perfectly clean rim.
I blame the Shinko 712s which were an experimental purchase I now wish I had not made. They are gone as soon as I can lay my hands on a 100/90-18 front and 110/90-18 rear from a brand of decent provenance. without a doubt the very worst tyres since the OEM Cheng Sings that came with (I think) the 400/4 I bought new in the 70s. (although that might have been the XS750). They are truly awful tyres.