The way I read this was that Syrian antiaircraft missles downed a Russian plane during an Israeli air attack on Syria. Russia is complaining that Israel should have notified them sooner about the attack so that the Russian plane would not have been in the same airspace. Because Israel did not notify them sooner, Russia is concluding that Israel intentionally did not inform them so that the Syrian air defenses would hit the larger Russian plane rather than the Israel fighters.
Sixty second notice was to hamper Russian ability to give the Syrian target a heads-up. Apparently the Israeli command believed the Russian C&C sufficiently competent to prevent this friendly-fire outcome?