Where is the line?

Recently I was walking through the parking lot of a certain institution towards the gate. Ahead of me walked a young man who I would not have noticed, had it not been for a brief interaction between him and a uniformed man I assume was a gateman or security guard.

So Young Man walked towards the gate and Mr Uniform approached him nonchalantly, not quite approaching but walking in the same general direction. As the two drew abreast of each other, their hands came close together for the briefest of moments and something passed from Young Man’s hand to Mr Uniform’s. Neither acknowledged the other, neither broke stride. Mr Uniform continued towards the gate and opened it. Young Man veered off to the right, unlocked one of several bodas parked there and rode out of the parking lot.

I only noticed this exchange because it happened right in front of me. It was so perfectly executed – like the scenes in the movies where the mole hands over company secrets to the other side – I would have applauded it had it not been for the questions it raised in my mind.

Most likely story behind what I had witnessed was that Young Man had to come into this place but was afraid to leave his bike outside and so Mr Uniform had allowed him to park it just within the gate for a fee, the payment of which I had just witnessed.

Maybe there was nothing untoward in the exchange. But if that was the case why had it been done so secretively? Of course one could argue that Mr Uniform was helping Young Man safe guard his source of livelihood, and Young Man was showing his gratitude.

Let’s broaden the scope a bit: Imagine Mr Uniform was not a guard at the gate of a public institution where anybody walks in and out. Imagine instead he was a security guard at a research facility, or a lawyer, a judge, a minister, a doctor, a pastor, a headmaster, or anybody else in a “position of power”.  Or Imagine Young Man was not a Boda Rider looking for safe haven for his bike, but a criminal, a businessman, an investor, a student, a spy, a patient, anybody else trying to get a “service”. Imagine the same furtive exchange happening, not in open parking lots but in “halls of power”. What if it was not a small note passed between hands but wads of notes passed in leather cases?

Where does one draw the line? Is it about the amount of money handed over, or the people involved in the transaction? Is it about the place, or the deed done? How does one measure what kind of deed requires what kind and amount of payment? At what point does this "extra payment for services rendered" change from simply gratitude to bribery or extortion? Does anyone know?