I think you could have drawn out the beer from underneath. But I understand the disgust factor.
One time a tiny fly got under the lid of a fermenter as I was setting it aside after racking to a keg. I had seen it flying around. Life got in the way and a week later I lifted the lid away and there was this fat bloated redly iridescent fly sitting there in the krausen ring. So fat it couldn't even fly away.
It was so swollen one could see the gaps in it's carapace and the skin in between.
No maggots thankfully.
I washed it down the drain with the rest of the gunk!