A fur shot does not cause a bounce. It can cause higher numbers because you've depleted the depot. When you think you might have done a fur shot, could you put that in the Units cell of the spreadsheet so it's easy to see? So you'd write 2.25 FS (for fur shot), so we know that's a possibility. And it does look like it because he went straight up after that. However, the depot should be established again after six cycles, so that shouldn't be an issue now cause today is the 7th cycle after the possible fur shot. You can't do anything after a fur shot, but wait it out.
What you are seeing today is a likely a bounce from a long stretch of yellows last night. Charlie has been stuck in pinks and reds so long that he's not used to even yellow any more. The "cure" is more insulin, and getting his body used to even lower numbers. With SLGS, you want him to regularly be seeing numbers between 90 and 149. Which brings up a question, why did you take the dose back to 1.0 units? That made his numbers worse and got him even more used to higher numbers. From the look of your spreadsheet, I suspect you got both the spreadsheet and the bad advice to "reset" to 1.0 units from a particular Facebook group. The format of their spreadsheet (which they took from us and modified), has a problem in it that causes it to blow up on several platforms. It's fine on my laptop, but blows on my iPad.
Anyway, that's in the past. Today is day 6 at this dose, I suspect that on day 8 you can increase back to 2.5 units.