accidentally on purpose
Deliberately, though apparently accidentally.
However, having accidentally-on-purpose got hold of a piece of the fish, down it went; and, apparently thinking that under the circumstances he might do worse, he set to work with
adv
In an accidental manner; by chance, unexpectedly.
He discovered penicillin largely accidentally.
Unintentionally.
He accidentally exposed the bacteria to mold spores.
As I arrived at the foot of the hill I overtook two ladies, whom I passed. As I did so, I brushed one of them accidently on the arm.