Quality is delighting customers
The best way is to send the bug report to the project manager because during the time of absence of the correspond developer, then the project manager will assign it someother person in their team if the bug has high priority.
You haven't mentioned how many QA people are on the project. I will assume that the number is equal to or greater than the number of developers.
Now, getting back to your question - your test strategy should list out a communication plan between the QA team and the development team. All defects should be assigned to the developers by ONE QA person. This eliminates confusion and also establishes an escalation channel if the significant defects cross the normal SLA time for resolution.