Engineer
He was a bit slower to react, as he'd just woke up, but he knew when something was going on. The police were here, for no explainable reason, and they had heavy ordinance. He could hear multiple vehicles and even a helicopter overhead. Had Mann Co. run into legal trouble? As in...a lot of legal trouble? Dell whipped his head around as Felice darted past, pushing Scout and Medic along, going into spawn long enough to yell a warning to pyro. Engineer darted inside his room briefly, grabbing his wrench and the only building he had stored in his room, a dispenser packed in an old toolbox, he pushed back out into the hallway just as Felice came back to him.
"We don't know what they want!" He called over the sirens, turning to look behind him as the cook started dragging him down the hall. "Maybe this is some big misunderstanding--" He tried to think of a reasonable solution, but when he heard unfamiliar yells, the doors breaking, he dropped the conversation. This wasn't some squaddie that got suspicious about all the gunfire, this was a full on bust, with men dressed in riot gear.
"Where are we going to go?" Engineer asked as he briefly saw Merasmus get surrounded by armed men. He winced, wanting to help, but Felice kept running and he couldn't stop. How could he, anyhow? He didn't have his guns, or his sentry. Unless they got within wrench range, he was harmless. They kept moving, Dell stumbling behind Felice as he started having trouble keeping pace, until they nearly reached the end of the corridor. He gripped the handle of the toolbox tighter, and didn't notice the canister until it was nearly too late.
He gasped and tried to kick it away from them, but it released the gas just before he could. He still kicked it away, but at least he'd gotten hit pretty badly. Smoke billowed up into his face and he cried out, dropping the toolbox and lifting a hand to try and scrub the chemicals from his eyes, only making it worse. He coughed violently and staggered towards Felice, trying to get out of the cloud.
"Agh! Ah, go! Keep movin'!" He struggled to say between coughs, lungs burning.