So last night I was playing around with different shouts in WvW to see what works the best. I have Save Yourselves, Retreat and Hold the Line equipped. If I use Hold the Line first, Save Yourselves cannot be used and is on the same cooldown as Hold the Line.
If I use Save Yourselves first, I am able to use Hold the line after that without any issues.
I just found that interesting, and wondered if anyone encountered this or know the reason for this?