As an end-user, it's impossible to resize the last column if a horizontal scroll is present (no gap at the end), as soon as you try to drag it, the drag ends immediately up against the scrollbar.
Tried on the latest Firefox & Chrome.
Try for yourself on the KendoUI demos:
1. Go to http://demos.telerik.com/kendo-ui/spreadsheet/index
2. Scroll all the way to the right.
3. Grab the last columns edge and attempt to resize.
4. Notice nothing is resized.