On Volskaya Foundry, all players will experience severely degraded connections leading to input delay and disconnects (200-900ms). It seems to coincide with Triglov spawning. Has happened a couple times to me in SL.
It was some DDoSing going on it seems.
Is Heroes of the Storm installed on a decent SSD? I think there is a loading spike when the protector spawns as it pulls in associated assets.
Either that or there is some sort of extra communication that occurs to allow for the cursor targeting of the passenger that is causing connection issues.