The results of the blobAs*() functions are not validated.
Here are some examples:
Non-type1 UUID inserted into timeuuid column:
create table foo (k int primary key, v timeuuid);
insert into foo (0, blobAsTimeuuid(0x00000000000000000000000000000000));
Blob with length > 4 inserted into an int column:
create table bar (k int primary key, v int);
insert into bar (k, v) VALUES (0, blobAsInt(0x0000000000));
Non-ascii characters inserted into an ascii column:
create table baz (k int primary key, v ascii);
insert into baz (k, v) VALUES (0, blobAsAscii(0xFFFFFFFF));
Some of these (like the int column) could cause issues that look like corruption.