Are the police invincible?

Yo heres the situation. I took my frined to the local babies r us. i am the godfather to her son and she wanted company with her so she could look for toys. we looked around for alittle while picked out some toys for 'lil man' and split up when we got to the cash register. she went to change little man while i grab the toys we'd bought and headed for the car. since she had walked into the staor before me when we arrived she would nt know where the car was parked. so i placed the toys inside of the car and i sat on top of its trunk waiting for her to come out. i must have waited for about ten or so minutes beofre i got tired of the heat and sat in the car. she showed up and banged on the window not a moment sooner than i had sat on the car. i let her in and we headed towards the macdonalds. (iexplained all of what i just did for a reason hang in there). At the drive through a cop pulled up behind me. It was a white guy with a typical cop expression. He asked for my liscense and insurance. i wa in my mothers car its sorta banged up so i wasnt too surprised by him stopping me. he ran my liscense through the machine i waited for another ten minutes then he came back. he handed my liscense back and said "i called the babies r us up the road and they said that you were in the parking lot begging." i was shocked, caught off gaurd so i tried to explain myself. he said "save it i could have given you two other tickets if i wanted to. TAKE YOUR LISCENSE." heres my question can officers pretty do or say anything they want to with a little bit of justification?