Rails - Why is this rolled back after a deadlock is detected in MySQL?

I have the following code in which a deadlock exception is rescued. In that rescue, I modify another record and save it. That save doesn't go through.

Is a transaction within rescue a nested transaction of the transaction in the begin?

begin
  Something.transaction do
    something.save # this causes a deadlock
  end

rescue StandardError => se
  # This gets called while rescuing a deadlock
  some_record.status = "updating"
  some_record.save # this seems to get rolled back
  puts se.error_message # Mysql2::Error: Deadlock found when trying to get lock; try restarting transaction:
end