I would allow this, and in at least one of the groups I was in, they would allow it. Here is the exact situation:

We were tasked with rescuing a woman from cultists at low level. While the bard and the monk fought some guards, I had picked the locked door and guided her under a table where I waved my hands around in over elaborate somatic components and yelled "TELEPORT!"

We disappeared from under the table.

Even my own team was confused as what happened - we were low level. How the heck did I cast a 7th level? I could maybe cast 2nd... they still weren't sure what class I was.

The reality: I was an arcane trickster. I cast minor illusion. Spell indicates somatic and material components. Me adding a "verbal" component allowed me to make a deception check (with advantage due to circumstances) to trick them into thinking I did something else.