I've seen that clip with all sorts of BS attached to it, like claiming it was the Israelis lighting up a Syrian tank in a day-to-day unchronicled combat along their border (Yeah, that really looks like the Golan, doesn't it?
).
I don't believe it's phosphorus at all, it appears to be a promotional shot of something like the Bofors Bill top-attack shaped charge missile (A HEAT warhead) striking a fully combat-loaded radio-controlled target vehicle. The fireworks aren't WP (which bursts in a huge star and then round cloud of smoke and burny bits immediately on impact), they are the propellant of the tank's basic load cooking off.
FWIW a tank doesn't need to get any closer than the far tree line, let alone the near tree line, to find and **** up a static position, and the Abrams doesn't carry its ammo in the same place as the obsolescent runner they used for this, it's kept behind a blast door in the rear of the turret, so even if the main gun ammo is hit, the crew isn't.
