Yeast explosion any reason to worry?

So I am fermenting a Yooper DFH 60min and I brewed last Sunday (5 days ago) and last night I swapped out my blowoff tube for a 3 piece because the bubbling had really slowed down. I woke up this morning to find yeast filled up through the airlock coming out the top and out the sides of the bung all over the carboy. I would have had quite a bit of solid yeast if I was wanting to rinse it.
I am not too worried, but wonder if there is any thing like pressure on the yeast or anything to worry about with this happening?

Also why would there not be any yeast traveling through the blowoff, but all of a sudden this explosion? Clogging?

Thanks

pics, or it didn't happen!

and no, the odds are the external push/pressure kept everything out of your fermenter.
you are fine, clean it up and continue as normal.
clog is the culprit.

Sorry no pics just a figment of my imagination.
Its weird though I see no activity with the blowoff. No bubbles or anything.