I also posted this in a swimming forum inadvertently…
+1 for garmin connect editing
Today I rode with my Edge 510. I forget to finish/save when I threw the bike in the back of the car (not the first time, especially when I'm exhausted).
Luckily I also transfer my cycling data to Strava. Strava even noticed that some of the data looked dodgy (like speeds > 100kmh), and offered me a cropping tool to fix it - easy peasy!