About what?
In the late 70s interception by a single fighter was common. In fact, seeing a flight of two was a rare thing when operating around the USSR. It was common to see a pair of Cuban MiG-21s. They were very good sticks. Can't say the same for the Soviet pilots of that time.
As for the RC crew seeing only one in this recent incident…had there been more than one they probably would have known it. It's what RCs do.
<edit> That's not to say that the US side is releasing everything they know about this incident. </edit>