Question regarding heap_multi_insert documentation

While reading the code for heapam.c:heap_multi_insert I happened upon this
comment which I'm either too thick for, or it lacks a word or two:

     * ..
     * A check here does not definitively prevent a serialization anomaly;
     * that check MUST be done at least past the point of acquiring an
     * exclusive buffer content lock on every buffer that will be affected,
     * and MAY be done after all inserts are reflected in the buffers and
     * those locks are released; otherwise there race condition.  Since
     * multiple buffers can be locked and unlocked in the loop below, and it
     * would not be feasible to identify and lock all of those buffers before
     * the loop, we must do a final check at the end.
     * ..

The part I don't understand is "otherwise there race condition", it doesn't
sound complete to me as a non-native english speaker.  Should that really be
"otherwise there *is a (potential)* race condition" or something similar?

cheers ./daniel