operation timeout is valid only for running transactions.

When transaction commit/rollback is performed, transaction release will be performed before engaging the callers for eviction. At this stage the transaction will not be running.

As a consequence the application thread invoking either the transaction commit/rollback will participate in eviction with out any time bound.
This breaks the WT contract that an API invoked by an application thread will honor the operation time out set, if any.

I think this is one of the reasons why we see sometimes mongo server trying to rollback the transactions will be stuck due to cache pressure and could lead to availability issue.