BJJ and Aikido
I don't know who you were playing with in your little wrestling match, but any good BJJ guy will force you to the ground ... of course, if you are scratching the eyes, poking the throat, hitting groan target #1, or other illegal moves for BJJ practice, that would be closer to my old Kempo practice.
Oh, and don't forget throwing your opponent across the room, against the wall or slamming them to the mat are no-no's also.
On the other hand, if your opponent used any of these distractions upon you, then I would be seeing a different story, maybe a more humble aikido practitioner?
I kind of liked the rough and tumble see what works on the ground practice of BJJ, it was eye opening enough to provide many balance, and unbalance points that translated into other Aikido techniques. It generally took jujitsu to another place that we don't always get time to explore, into a bloody streetfight/wrestling arena.
Just about anyone who says they only do Aikido usually freezes when grappled, my hat is off to you for not freezing, good job.
You shouldn't be cocky about though, because some little guy, who really looks like nothing, will probably beat your ass, and it will be because you were not respectful of BJJ?
On the other hand, if you are both just beginners, trying each others previous style, and looking for ways to adapt or overcome, it was a good lesson for winner and loser.
I probably shouldn't have said anything, but we are humble, respectful of other arts when we show Aikido, aren't we?
I was just kidding, there won't be a little guy from Brazil to beat you up ...
Maybe three big guys who want to have words with you and set you straight, but no little guy.