Determine compression used on Tiff file

try it for file:

#target photoshop
var f = new File('e:/_output/testfile.tif'),
    compression = { 1: 'uncompressed', 2: 'CCITT', 5: 'LZW', 7: 'JPEG', 8: 'ZIP' }

ExternalObject.AdobeXMPScript = new ExternalObject('lib:AdobeXMPScript')
xmpMeta = new XMPFile(f.fsName, XMPConst.FILE_TIFF, XMPConst.OPEN_FOR_READ).getXMP()

alert(compression[xmpMeta.getProperty(XMPConst.NS_TIFF, 'Compression')])

or for opened document:

#target photoshop
var compression = { 1: 'uncompressed', 2: 'CCITT', 5: 'LZW', 7: 'JPEG', 8: 'ZIP' }

ExternalObject.AdobeXMPScript = new ExternalObject('lib:AdobeXMPScript')
xmpMeta = new XMPMeta(app.activeDocument.xmpMetadata.rawData)

alert(compression[xmpMeta.getProperty(XMPConst.NS_TIFF, 'Compression')])

Perhaps reading the input file list as binary data and or hex and searching the content for the files that don't use the TIFF tag for LZW compression... I have seen similar tricks in Bridge scripting when looking for other specific data embedded in the file, but can't help much beyond that.

ExifTool can easily find the compression method used in a TIFF file, for example for a file with LZW:

Compression = 5
Tag 0x0103 (2 bytes, int16u[1]):
0042: 00 05

So the data must be there, it would be easy enough for ExifTool to flag these images using a label or rating or other metadata, however, this is far from ideal.

https://www.adobe.com/devnet-apps/photoshop/fileformatashtml/#50577413_pgfId-1035272

Good luck!