When you record long videos on your Bandit, the video gets split into smaller sections rather than having one continuous recording. The length of each section differs across video modes, but each section is roughly 4Gb in size.
This is a limitation of the file system used on your micro-SD card, which is either FAT32 or exFAT format. FAT32 is the most widely compatible file system across Windows, Mac OS or Linux but has a limitation of only supporting file sizes of up to 4Gb.
When you are shooting high definition videos this limit is reached quickly. To allow you to use your recordings on your computer, they are split into smaller sizes in order to be compatible.