When the castaways are eating soap at the table, the device used by the professor to measure radiation disappears between camera shots.
Mr. Howell praises Ginger on how she prepared the artichokes. However, in the later installment "The Second Ginger Grant" she is an awful cook.
The castaways talk of how much they've missed vegetables. However, in at least two past installments, they had celery, green beans, etc.
To lighten the soil for the vegetables to grow better, Gilligan adds sand from the edge of the lagoon. However, that sand would also contain enough salt to kill the vegetable seeds they intend to grow.
When everyone is at the table eating the soap, just before Gilligan starts making bubbles, the pipe at the back of his neck that is used to produce the bubbles is briefly visible. Also, Mary Ann's and the professors clearly do not come from their mouths, but beyond their left cheeks.
When Gilligan is lifting Skipper, the wires attached to the lounge chair can be seen behind Skipper's head on the close up shot.
When Gilligan tosses the coconut to the Skipper, the section of the hut which gets impacted starts to move before the coconut reaches it. In addition, the fishing line on which it travels can be seen glistening behind the Skipper's head.
Unless Gilligan had his eyes closed when he removed the crate's cover and when he made it into a bench, there is no way he wouldn't have seen the radioactive seed warning.