A MANPAD could. Am I wrong Marine/Army types? What about a Javelin?
Wrong size warhead and damage effect.
The mortars were placed in preregistered spots allowing predialed data to be fired on thus allowing a pretty reasonable mathematical chance of a hit.
I was towed artillery, some of the info and usage is similar between light towed and mortar disciplines.
You can mathematically compute distance to target, amount of powder, and warhead weight to generate a rough and tumble idea of where it will go.
There are computational tables used to make this even easier.
I think I saw one online not too long ago.
If any mortarmen are around, they may be able to elaborate on the actual mortar side of things.
Mortars are indirect fire weapons. ManPads and the Javelin are missiles. The older SA missiles use a infared seeker head that guides after launch. The Javelin has a fire and forget feature that can terminally guide the missile. If you can get the lock, shooting from a truck wouldn't matter. The backblast might cause a problem.
The statement is also somewhat odd in that the US mounts all kinds of direct fire weapons on vehicles and not all are stabilized. They still are effective.
These people are all nutz including Schaffer. The whole idea of a small mortar, say 60 mm, is to fire and scoot. With a decent sight it can hit a swimming pool repeatedly, in a truck or rickshaw or on a mule, every thirty seconds or so. The real test however is what kind of wounds actually killed the guys on the roof. The second test is whether or not the rounds contacted the roof or hit something like a person on the way down. If the rounds hit the roof then there should be a hole in the roof to match. In none of the pics of the building has any roof holes been evident. Until we see actualy physical evidence the rest is all hokum upon which I threw the BS flag long ago.