Firstly, I'd like to note that you could change your script to
OP_1 OP_1 OP_BOOLAND OP_IF OP_RETURN OP_ENDIF and it would be the same.
I'm reading the bitcoin source code, and I can't see a check for nested OP_IF's. These are the IF related checks I've found:
- No IF/NOTIF without a value on the stack
- No ELSE/ENDIF without an IF/NOTIF
- No IF/NOTIF without an ENDIF
So it would let you nest IF's. In fact, it appears that allowing people to nest IF's is intended. Take this variable, which is used to figure out whether a branch of an IF is executing:
If they didn't want nested IF's, they could have made that a single
Amusing fact that I figured out while researching this: The script
OP_1 OP_IF OP_ELSE OP_ELSE OP_ENDIF is entirely valid.