He never responded?
The 81 is a semi-portable mortar. Three dudes can carry it although each part is pretty heavy and the ammo is not exactly helium balloons either. So you'll find it "organic" with the troops not so much 20 miles behind the lines. Anyway it's "theirs" so they tell their crew what to do rather than some arty support guy coordinating with the aircrew. Thats why the pilot coordinates with the ground troops telling them to keep firing or cease firing during the airstrike, rather than coordinating with the naval 16 inch battleship guns and the ground troops have no direct involvement in the conversation.
So a good use of a mortar is area denial, keep down and stop moving or you'll get blown up. So you find a concentration of troops and pin them down with a mortar every XYZ seconds and call in an airstrike. Mortars shoot almost straight up so they're indirect fire, you can plink away all day and the enemy can do nothing about it unless they have indirect fire capability (like their own mortar, or their own close air support, or arty support, etc). You can try suppressive fire with a machine gun, but the ammo is really heavy and its direct fire so if you can fire on them, they can fire on you, western gunfight style, so its kinda hazardous. So if you're a ground troop, and you've got an indirect fire weapon like a mortar, you will greatly enjoy using it compared to the alternatives.
Most pilots are unamused at the idea of flying thru actively firing artillery. So stop firing the mortar and hope the enemy doesn't do something bad until the airstrike arrives... Bad being anything from a massive counterattack, or charging your position, or maybe hiding from the airstrike really well. If the enemy does pretty much anything but lay there, its probably bad for the troops on the ground. On the other hand there's a 1 in a zillion chance of the aircraft getting hit by a mortar round or fragments.
The A10 guys let them just keep firing mortars while they attack unlike other pilots.
From a complimentary position, obviously a 400 knot fixed wing aircraft has less than 1/4 chance that a 100 knot helicopter has of accidentally getting hit. And its much more heavily armored than a delicate modern fighter, so taking a hit doesn't really matter as much. Its a flying tank, basically, and/or the pilots are a bit more aggressive so they are willing to take more risks.
Not entirely complimentary, as the A10 guys might also be saying that an incoming modern surface to air missile is more lethal overall than getting hit directly or indirectly off their own guy's mortars. Something like getting a 1 in a million accidental hit from a mortar is less dangerous than a 1 in a hundred hit from a modern enemy surface to air missile. So the mortar fire is stopping the enemy from preparing and firing a SAM at the incoming aircraft. Who's protecting who, exactly?
From the ground troop perspective, anytime somebody doesn't stop you from suppressive fire is a universal good, so that's why they like the A10 so much, regardless of reason.