that's actually not weird if you know the sprites effect according to a list in SEN when you disable a exct/ref/assimi/ you will have that hallucination thing the same if you do it to the geyser you will hear "our base is under attack or something" you try to lockdown a mineral field and will do the same thing hmm it got me thinking about a way to create a half build building when it's about to created woot let me test this idea results will be posted in a bit
ADDITION:
RESULTS:
you give a marine or any other unit lockdown as weapon get a scv to build let's use comand center when it's building chose how you want it to stay then attack the building with the marine so now it's lock down but the scv is still building now lock him down too when they get back the scv will still be building but with no spark and it won't move to any other place give the scv the order "cancel construction" it will stop and the building will stay everybody will say it's the same thing as normal but if you notice you now have the lift building icon instead of cancel construction
pity you can't use it but it will be cool
ADDITION:
have fun with other buildings and try protoss too and tell me if they crash