Dark souls question

Can I be summoned in other players games while in human form?

At one point i was hollowed, layed down my sign, said forget it used a bonfire to turn human, a second later it starts summoning me into someone elses game. I stayed, we killed the boss then i was returned in human form. A glitch i can understand. But was i always able to lay down my summon sign while humen?

Since my return I've seen noone to summon. And i cant remember if i could always lay my stone down while humen to be summoned. I just wana know if im under the control of some glitch.

Ok good. I was worried the glitch messed up my game or something.

But since it didnt it was in interesting slip up.

thx.