To be fair ANY contact can potentially cause a trip or fall, its just a matter of timing , point of "entry" , and whether you're making contact with Drogba or with Iniesta, if you get my meaning
I played at this game back at college (cool story bro, i know). Entire game I went really rough shoulder to shoulder with defender , good 40 minutes with nothing happening. At some point he just barely touched me when i was changing directions while on full speed and i flew in the air like Superman. We had no professional ref, the other team said i dived, my team said i almost died, and it ended up with a little team on team brawl.