The bootloader is provided with 2 - 1 gas to execute all submitted transactions in a given batch, so it is expected that all the gas refunds will be below that amount. For L2 transactions, it is checked in:
bootloader, lines 1463 to 1465
But for L1L2 transactions it is not enforced, leading to a possible situation in which the operator refunds, or even pay himself, more than what the bootloader really has. Consider doing in:
bootloader, line 926
