Considering that it was messy when Charlie tried, who knows...

Was it after the boss has appeared in the room...?

Yes. I spawn in, the fight starts (with sped up boss) and the mod crashes after the boss jumps.

Here's the full script for reference:
#0299
<MNA<DNP0299<EVE0300<END
#0300
<FAI0003<CMU0022<BOA0020<WAI0001<BOA0010<WAI0001<BOA0100<BSL0000<SMC<CNP0300:0363:0000<END
#1000
<KEY<BOA0130<DNA0110<DNA0104<WAI0420<CMU0010<DNP0402<MSGYou've defeated the Diamond Dogs!<FMU<NOD<CLR<EVE1001<END
#1001
<ITJ0022:1003<AMJ0007:1002<KEY<SAT<MSG<FAC0009Impressive.Our master's plan
grows ever closer. Our Boss
Weapon will now be yours...<DNP0402<NOD<CLR<TRA0009:0091:0012:0007<END
#1002
<TRA0009:0091:0008:0015<END
#1003
<TRA0092:0095:0010:0014<END