It's probably for the best you guys didn't use the newer version 34 of platform tools to update, as Google seem to have done something funky with it where it's not rebooting into fastbootd, and thus the final few step of flashing the important patiations fails as it tries but is unable to flash them as one large "super" sparse, or whatever the hell it is trying to do. Trying to boot after this just ends up in a bootloop.
While I was trying to manually flash the 3.1 beta (as it's not on the android flash tool website for some reason), while trying to figure out the problem I also tried the new stable build, seeing as I had already done a full wipe as a precaution at first not knowing what the problem was.
extracting android-info.txt (0 MB) to RAM...
Checking 'product' OKAY [ 0.000s]
Checking 'version-bootloader' OKAY [ 0.000s]
Checking 'version-baseband' OKAY [ 0.000s]
Setting current slot to 'b' OKAY [ 0.120s]
extracting boot.img (64 MB) to disk... took 0.191s
archive does not contain 'boot.sig'
Sending 'boot_b' (65536 KB) OKAY [ 1.465s]
Writing 'boot_b' OKAY [ 0.257s]
extracting init_boot.img (8 MB) to disk... took 0.025s
archive does not contain 'init_boot.sig'
Sending 'init_boot_b' (8192 KB) OKAY [ 0.180s]
Writing 'init_boot_b' OKAY [ 0.032s]
extracting dtbo.img (16 MB) to disk... took 0.095s
archive does not contain 'dtbo.sig'
Sending 'dtbo_b' (16384 KB) OKAY [ 0.364s]
Writing 'dtbo_b' OKAY [ 0.057s]
archive does not contain 'dt.img'
extracting pvmfw.img (1 MB) to disk... took 0.011s
archive does not contain 'pvmfw.sig'
Sending 'pvmfw_b' (1024 KB) OKAY [ 0.024s]
Writing 'pvmfw_b' OKAY [ 0.007s]
archive does not contain 'recovery.img'
extracting vbmeta.img (0 MB) to disk... took 0.002s
archive does not contain 'vbmeta.sig'
Sending 'vbmeta_b' (12 KB) OKAY [ 0.001s]
Writing 'vbmeta_b' OKAY [ 0.003s]
extracting vbmeta_system.img (0 MB) to disk... took 0.003s
archive does not contain 'vbmeta_system.sig'
Sending 'vbmeta_system_b' (4 KB) OKAY [ 0.001s]
Writing 'vbmeta_system_b' OKAY [ 0.003s]
extracting vbmeta_vendor.img (0 MB) to disk... took 0.001s
archive does not contain 'vbmeta_vendor.sig'
Sending 'vbmeta_vendor_b' (4 KB) OKAY [ 0.001s]
Writing 'vbmeta_vendor_b' OKAY [ 0.002s]
extracting vendor_boot.img (64 MB) to disk... took 0.255s
archive does not contain 'vendor_boot.sig'
Sending 'vendor_boot_b' (65536 KB) OKAY [ 1.466s]
Writing 'vendor_boot_b' OKAY [ 0.247s]
extracting vendor_kernel_boot.img (64 MB) to disk... took 0.169s
archive does not contain 'vendor_kernel_boot.sig'
Sending 'vendor_kernel_boot_b' (65536 KB) OKAY [ 1.491s]
Writing 'vendor_kernel_boot_b' OKAY [ 0.269s]
extracting super_empty.img (0 MB) to disk... took 0.002s
extracting product.img (2870 MB) to disk... took 15.960s
extracting system.img (827 MB) to disk... took 4.945s
extracting system_dlkm.img (0 MB) to disk... took 0.001s
extracting system_ext.img (361 MB) to disk... took 2.279s
extracting system_other.img (25 MB) to disk... took 0.181s
extracting vendor.img (644 MB) to disk... took 5.272s
extracting vendor_dlkm.img (41 MB) to disk... took 0.122s
archive does not contain 'vendor_other.img'
Sending sparse 'super' 1/1 (4194303 KB) FAILED (Sparse file is too large or invalid)
fastboot: error: Command failed