What scared the Coyote?

What scared the Coyote as he passed my WOC on the trail behind my house?

I see Coyotes almost every night, passing two of my WOC cameras on that trail.

They have never flinched like this in front of one of my WOCs. 19 minutes after the Coyote is startled the same Coyote or its twin passed by the WOC in the same location/direction and walked by just like the WOC wasn’t there, which is normal (except for the first time I placed the WOCs on the trail, every raccoon or coyote that walked by noticed it the first time, and then ignored it afterwards)