They find the person shopping or something, routine. Spritz some flu into their face. (Well, more discretely, but yeah.)
They go to the hospital, pay the guy a visit when, spritz some MRSA on his linens or something. Plenty of opportunity. Even better, spritz it on everyone’s linens so it looks like an outbreak.
Slip in, visit the guy and inject a stroke causing drug. Maybe even something as innocuous as just injecting an air bubble into his artery.
Maybe a small support team. But really, you think Boeing doesn’t already have a hitter on the payroll?