^^^ He's initially trying to cut too fast and deforming the can, and quit before the can was fully cut. Thinner cans will try to deform if trying to cut too fast. Better to go with less wheel bite than more.
I was chuckling until the dude broke out the utility knife and started working, then I cringed. One word came to mind watching much of the video. Clueless.
Otoh, it does make me feel good about my Taiwan made Harbor Freight Exhaust Cut Off tool with four cutting wheels. Purchased over a decade ago (~$15) for use as a filter cutter. With a little finesse, still works well.
Just to show how much us Canuks get ripped, the exact filter cutter that's US$22 ( CAN$30) is CAN$56 in Canadustan which is US$42. Sorry to interrupt, it just pi$$es me off.