One of the Carbon reps on 2p2 said the maintenance was done out of necessity, and it got pushed early. Obviously they wouldn't usually do maintenance at one of their busier times of the week.
Here is Carbon's Disconnection Policy:
Game cancellation policy:
Occasionally, there is a need to cancel certain games on our severs. When games are cancelled, refunds and prizepool payouts will occur as follows:
COMMUNITY/PRIVATE GAMES: Each player will be refunded the exact amount of money he or she had at the start of the hand at the time of cancellation.
SINGLE-TABLE TOURNAMENTS: If a Single-Table Tournament is cancelled for technical reasons:
Players who were eliminated prior to cancellation will not be refunded in any way and will not receive any prizepool dividends.
Players that were active in the tournament at the time of cancellation will receive:
The entry fee refunded
The buy-in refunded from the prizepool
If the guarantee was exceeded or prizes had been paid, a share of the remainder of the prizepool: 50% distributed equally and 50% distributed based on stack size at time of shutdown
If the guarantee was not met and prizes had not been paid, a share of the sum of an adjusted prizepool containing all non-refunded buyins, rebuys and addons: 50% distributed equally and 50% distributed based on stack size at time of shutdown
MULTI-TABLE TOURNAMENTS: If a Multi-Table Tournament is cancelled for technical reasons:
Players who were eliminated prior to cancellation will not be refunded in any way and will not receive any prizepool dividends.
Players that were active in the tournament at the time of cancellation will receive:
The entry fee refunded
The buy-in refunded from the prizepool
If purchased, rebuys will be refunded from the prizepool, unless the rebuy was purchased for re-entry to the tournament after being knocked out
If purchased, addons will be refunded from the prizepool
If the guarantee was exceeded or prizes had been paid, a share of the remainder of the prizepool: 50% distributed equally and 50% distributed based on stack size at time of shutdown
If the guarantee was not met and prizes had not been paid, a share of the sum of an adjusted prizepool containing all non-refunded buyins, rebuys and addons: 50% distributed equally and 50% distributed based on stack size at time of shutdown
FREEROLL TOURNAMENTS: If a Freeroll Tournament is cancelled for technical reasons:
Players who are eliminated prior to cancellation may not be eligible for any further compensation.
Players that were active at the time of the tournament cancellation will receive:
An entry to another instance of the same tournament, to be re-run at a time of CarbonPoker’s choosing
An entry to a similar tournament, run at a later date, at the discretion of CarbonPoker.