For some unknown reason, these two sentences:
1a. The report describes the problems at the firm, blaming specific employees.
1b. The report describes the problems at the firm and it blames specific employees.
are close in meaning.
But these two sentences:
2a. He refused the offer, knowing that the offer was a trap.
2b. He refused the offer and he knew that the offer was a trap.
are not as close in meaning. So, the two nonfinite adverbial clauses above have different functions and meanings?