Can stable owners kick out boarded horses ?

Yesterday I boarded 8 of my horses in the same stable, then trained them. Today I progressed my account and wanted to train them again but received a message that they need to be boarded at a stable before training...? I checked those horses and all of them turned out to be without board...?
Is it possible that a stable owner kicked out my horses ??? And what would be his/her reason to do it, since they had just been boarded so clearly weren't late with payment...?

<sup>You can only be kicked out manually if you run out of boarding days. 

Horses also get kicked out if the owner loses their deluxe and loses the stable.</sup> 

I remember wondering whether to lock them or not and I'm not clear about it but it is possible that I locked them in a division for a few hours but then unlocked them. Does locking horses causes them to loose boarding ?

^{Yes locking horses will also kick them out of their stables (went to test myself as I couldn't remember if it did or not). If you don't progress they'll count down their boarding days but not if you lock them.} 

Thank you :)