Very inventive on your part
Great video you've found in terms of its "here is what not to do, folks" educational value, I think.
The pacu was too cocky. The tinfoil is smaller and would have been 10x easier to swallow but he must have been more alert and wary of the RTC. Yet, in such a small tank, it is only a matter of time. Still the pacu could not be swallowed, too big.
So this is what happened with yours except your pacu died? So your pacu has never been swallowed and eaten but simply held in the mouth and likely suffocated? If so, that changes my entire perspective on your story and I'd find this more believable, no offense meant.