I work in a warehouse packing parcels for a large ebay & amazon seller, on my first day of work I went outside to have a
vape with a new guy who also vaped we chatted a bit, next thing I know my manager comes out telling me 'That's not smoking!!' - I felt a bit worried because of his tone of voice, maybe he thought I was just trying to slack off or something, to my surprise his tone changed and he then said you can vape inside with a smile on his face
On-topic; You should take others advice, if you value your job and don't want to risk it even though you feel the risk is low, don't risk it. You value your job, and that should be enough.