It's not like Ellis hasn't had a chance to test his powers, given to him in strange ways that he doesn't remember consenting but welcomed nonetheless. He's been acting his revenge on those who took his entire family and loved ones. He has a hit list and President Snow is on the top.

He's under cover in the District of Luxury, a fashionably hooded jacket kept him from being watched: he knows he's on the Capitol's wanted list for a while now. When he spots Ermac, floating about, he's torn. He should kill any and all enemy combatants...but this is his friend dammit! And he should minimize the death tolls.

So he instead gives chase, whistling towards the officers and runs off to the nearest park, away from civilians.